Dosing regimen for sedation with cns 7056 (remimazolam)

ABSTRACT

The invention relates to a dosing regimen for sedation with the fast-acting benzodiazepine CNS 7056 in combination with an opioid, in particular fentanyl, whereas CNS 7056 is given in a dose of 2 to 20 mg, preferably between 4 and 9 mg and most preferably between 5 and 8 mg.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/883,935, having a 371(c) date of Sep. 10, 2013, which is a 35 U.S.C.371 national stage filing of International Application No.PCT/EP2011/005581, filed on Nov. 7, 2011, which claims priority to thefollowing European Patent Applications: Serial No. 10 014 366.8, filedon Nov. 8, 2010; Serial No. 10 014 784.2, filed on Nov. 19, 2010; SerialNo. 10 014 819.6, filed on Nov. 22, 2010; and Serial No. 10 014 972.3,filed on Nov. 25, 2010. The contents of the aforementioned applicationsare hereby incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION

The invention relates to a dosing regimen for sedation with thebenzodiazepine3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-a][1,4]benzodiazepin-4-yl]propionic methyl ester (CNS 7056; Remimazolam) in combination with anopioid, in particular fentanyl.

Sedation is a medical procedure involving the administration of sedativedrugs to facilitate or enable a therapeutic or diagnostic procedure on aliving subject. Sedation represents a hallmark of modern medicine and iswidely used with its application ranging from minor surgery ordiagnostic procedures up to ventilation of patients in intensive careunits. Several classes of sedatives are known; among thembenzodiazepines, which are often used and administered in combinationwith opioids. This combination represents the current gold standard forsedation.

The identification of an optimal dose and dosing regimen represents themost critical point when using sedatives. This is due to the highvariability of blood concentrations together with high inter-individualdifferences in response to sedative drugs. Hence, the clinician canexpect the range of individual patient response to vary between three-to fivefold for any particular sedative or analgesic agent.

Because of this variable response, the generally recommended procedurefor a clinician attempting to achieve optimal sedation is to administeran initial bolus and then titrate the drug to the patient by incrementaldosing until the desired level of sedation is achieved. The resultingdosing regimen which defines the initial and subsequent top-up doses andthe time interval between the doses has to consider the drug'sparticular pharmacokinetic and pharmacodynamic properties, and has to bespecifically adopted to the utilized sedative compound. Finally, theroute of administration has to be defined (e.g. intravenous, oral,rectal, intramuscular, etc.).

Finding a suitable dosing regimen is particularly challenging if thesedative is used in combination with an opioid for the induction andmaintenance of adequate sedation. At first, benzodiazepines and opioidsinteract with regard to the induction of sedation. Therefore, theadministration of an opioid can reduce the amount of a benzodiazepineneeded to achieve the desired level of sedation. Furthermore,benzodiazepines and opioids have additive or even synergistic effectswith respect to their side effects, which increase the risk of adverseevents, including hypotension, ventilatory depression and resultanthypoxemia.

As a consequence, a fixed combination of sedative and analgesic agentsusually is considered to not allow the individual components ofsedation/analgesia to be appropriately titrated to meet individualrequirements of the patient and procedure, while reducing the associatedrisks, but rather maximum doses are recommended for the combination.

Recently, a new class of benzodiazepines was developed and disclosed inEP 1 183 243 B1. This class of benzodiazepines represent potentsedatives which are rapidly metabolized by tissue esterases to aninactive metabolite and thus were classified as ultra-short-activebenzodiazepines.

The compound3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-a][1,4]benzodiaze-pin-4-yl]propionic methyl ester (hereinafter “CNS 7056”) represents one of theseultra-short-acting benzodiazepines (disclosed as example lc-8 of EP 1183 243 B1). CNS7056 was tested in clinical Phase I and Phase II studieswith and without combination with fentanyl for producing sedation forendoscopy or colonoscopy, wherein CNS 7056 was given as body-weightadjusted dose. In these studies (CNS 7056-001, CNS 7056-002 and CNS7056-003) CNS 7056 exhibited a fast-onset, short duration of action andrapid recovery profile.

In these studies, however, also certain deficiencies or risks withregard to the suitability of the sedation profile and tolerabilitybecame apparent. In CNS 7056-002, which was a multiple dose study,individual MOAA/S scores indicated a drop of levels to loss ofconsciousness (LoC) in most subjects at some point in time after theinitial and/or top up doses.

Furthermore, the sedative effect exhibited significant variability. Afew subjects were classified as “dropouts” (subjects who never had aMOAA/S score below or equal three despite two top-up doses) and at thesame time one subject was classified as failure (underwent colonoscopybut reached full alertness, i.e. having a MOAA/S score of five).

In some cases mild hypoxic events were observed under room airconditions.

In some cases hypotension was observed when CNS 7056 was co-administeredwith fentanyl. Hypotension is one of the known side effects of fentanyl.However, since hypotension is also known to occur after high doses ofbenzodiazepines, a potential augmentation of the fentanyl-inducedhypotension effect by CNS 7056 has to be considered.

Thus, an optimised dosing regimen for CNS 7056 is required.

BRIEF SUMMARY OF THE INVENTION

It is thus the objective of the present invention to provide aconvenient and safe dosing regimen for the ultra-short-actingbenzodiazepine CNS 7056 which also results in an improved sedationprofile.

This objective is solved by the use of3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-a][1,4]benzodiazepin-4-yl]propionic methyl ester (CNS 7056), according to formula (I)

or pharmaceutically acceptable salt or solvate thereof for the inductionand/or maintenance of sedation, whereby CNS 7056 is administered incombination with an opioid wherein an initial dose of CNS 7056 is 2 to10 mg.

The dosing regimen of the invention is advantageous in terms ofminimising the rate of “drop-out” subjects with MOAA/S scores of zero aswell as the rate of “failures” (subjects whose sedation was notmaintained satisfactorily for 60 minutes, preferably for 45 minutes andmost preferably for 30 minutes with 6 top-up doses).

Furthermore the dosing regimen of the invention has considerablepharmacoeconomical advantages, because due to the rapid recovery of thepatients (a short wake up time to fully alertness) the patients can bereleased rapidly. The time from last injection of CNS7056 until thepatients are ready for discharge can be considerably shorten comparedwith the sedation with midazolam.

DEFINITIONS

The term “sedation” refers to a relaxed, calm state of the body and mindwhich is induced pharmacologically, e.g. by the use of sedatives. Thisalso encompasses “analgosedation” which includes the concomitantapplication of an analgesic drug. Furthermore, as defined herein, theterm sedation includes also deep sedation, preoperative sedation,anxiolysis, and amnestic use for perioperative events, conscioussedation during short diagnostic, operative or endoscopic procedures,and sedation prior and/or concomitant to the administration of otheranaesthetic or analgesic agents.

The phrase “treated or administered in combination” as used herein forthe combined therapeutic use or administration of CNS 7056 and an opioid(e.g. fentanyl) means that at least one dose of CNS 7056 and at leastone dose of an opioid is given within a time frame, where bothsubstances exhibit a pharmacological effect. This time frame ispreferably not longer than 10 min, more preferred not longer than 8, 5,or 3 min. In one embodiment the time frame is less than 2 min. Theopioid and CNS 7056 may be administered concomitantly or sequentially.This phrase encompasses treatments in which CNS 7056 and the opioid areadministered either by the same route or different routes ofadministration.

The term “analgesia” as used herein refers to the pharmacologicallyinduced absence or deadening of the sense of pain, e.g. by the use ofanalgesics, such as opioids.

The term “fixed dose” as used in the present invention relates to anamount of a drug given to a patient irrespective of his body weight.

As used herein the term “initial dose” is synonymous to the term“loading dose” and is defined as the first dose of a drug given in thecontext of a medical sedative treatment.

The term “top-up dose” relates to a dose given after the initial dose ora previous top-up dose in the context of a medical treatment.

The term “minimal sedation” or “mild sedation” refers to a drug-inducedstate during which the patient responds normally to verbal commands.Cognitive function and coordination may be impaired. Ventilatory andcardiovascular functions are unaffected. Minimal sedation is also knownas anxiolysis.

The term “moderate sedation” (synonymously with conscious sedation)refers to a drug-induced depression of consciousness during which thepatient responds purposefully to verbal command, either alone oraccompanied by light tactile stimulation. No interventions are necessaryto maintain a patent airway. During moderate sedation spontaneousventilation is adequate and the cardiovascular function is usuallymaintained.

The term “deep sedation” refers to a drug-induced depression ofconsciousness during which the patient cannot be easily aroused, butresponds purposefully following repeated or painful stimulation.Independent ventilatory function may be impaired. The patient mayrequire assistance to maintain a patent airway. During deep sedation thespontaneous ventilation may be inadequate and cardiovascular function isusually maintained.

The term “procedural sedation” refers to a technique of administeringsedatives or dissociative agents with or without analgesics to induce astate that allows the patient to tolerate unpleasant procedures whilemaintaining cardio respiratory function. Procedural sedation andanalgesia is intended to result in a depressed level of consciousnessthat allows the patient to maintain oxygenation and airway controlindependently.

The term “analgosedation” refers to a pharmacologically inducedanalgesia with concurrent sedation. In contrast to the anaesthesia thepatient can react on external stimuli and breathe unaided. Dependent onthe dose of the sedative and/or the analgesic drug the analgosedationcan, intentionally or not, reach the state of general anaesthesia.

The term “general anesthesia” refers to a drug-induced loss ofconsciousness (LoC) during which the patient is not arousable, even topainful stimuli. During general anesthesia the ability to maintainindependent ventilatory function is often impaired and assistance isoften required in maintaining a patent airway. Furthermore, positivepressure ventilation may be required due to depressed spontaneousventilation or drug-induced depression of neuromuscular function andcardiovascular function may be impaired.

The term “monitored anesthesia care” as used herein refers to a specificanesthesia service for a diagnostic or therapeutic procedure whichincludes the following aspects of anesthesia care: (i) a preprocedurevisit, (ii) intraprocedure care, and (iii) postprocedure anesthesiamanagement. During monitored anesthesia care, the anesthesiologistprovides or medically directs a number of specific services, includingbut not limited to diagnosis and treatment of clinical problems thatoccur during the procedure, support of vital functions, administrationof sedatives, analgesics, hypnotics, anaesthetic agents or othermedications as necessary for patient safety, psychological support andphysical comfort, and provision of other medical services as needed tocomplete the procedure safely.

Monitored anesthesia care may include varying levels of sedation,analgesia, and anxiolysis as necessary. The provider of monitoredanesthesia care must be prepared and qualified to convert to generalanesthesia when necessary. This is the case, when the patient losesconsciousness and the ability to respond purposefully, irrespective ofwhether airway instrumentation is required.

For assessment of the various states of sedation and analgosedation theso called Modified Observer's Assessment of Alertness and Sedation scale(MOAA/S) and, alternatively, the Ramsey Scale often are used. Thesescales are as follows:

Responsiveness Score Modified Observer's Assessment ofAlertness/Sedation Scale Agitated 6 Responds readily to name spoken innormal tone (alert) 5 Lethargic response to name spoken in normal tone 4Responds only after name is called loudly and/or repeatedly 3 Respondsonly after mild prodding or shaking 2 Does not respond to mild proddingor shaking 1 Does not respond to deep stimulus 0 Ramsey Sedation ScalePatient is anxious and agitated or restless, or both 1 Patient iscooperative, oriented and tranquil 2 Patient responds to commands only 3Patient exhibits brisk response to light glabellar tap or 4 loudauditory stimulus Patient exhibits a sluggish response to lightglabellar tap or loud 5 auditory stimulus Patient exhibits no response 6

The term “opioid” which is synonymous to the term “opioid drug” as usedherein refers to compounds which have the same mode of action as theconstituents of opium, the dried milky liquid of the poppy seed, Papaversomniferum. All opioid drugs interact in biological systems with thesame type of receptor, the so called opioid receptor. According to theanalgesia and side effect profile five types of opioid receptors, theμ-receptor (ligand=morphine), the κ[kappa]-receptor (ligand=ketazocine),the delta-receptor (ligand=deltorphine II), the σ[sigma]-receptor(ligand=SKF 10081), as well as the later-identified ORL1-receptor(ligand=nociceptin) are known. Corresponding to other receptor systems,binding studies as well as functional investigations indicate thatsubtypes of opioid receptors exist. Within the μ- and δ-receptor type 2subtypes, the μ-1 and μ-2 and δ-1 and δ-2 have been described. Theκ-receptor contains an additional κ-3 subtype. Especially in regards tothe μ-opioid receptor its two subtypes are included in this invention.

The term “endoscopy” refers to techniques used to inspect or to lookinto internal cavities or hollow structures of an organism.

The term “upper GI endoscopy” refers to an examination of the inside ofthe upper gastrointestinal tract such as the oesophagus, stomach and/orduodenum. It is typically performed by using a thin, flexiblefibre-optic instrument that is passed through the mouth and allows theobservation of the lining of the oesophagus stomach and/or duodenum. Itis also referred as esophagogastroduodenoscopy (EGD) or gastroscopy. Theupper GI endoscopy also includes other GI procedures such as theendoscopic retrograde cholangiopancreaticography (ERCP).

As used herein the term “colonoscopy” refers to an endoscopicexamination of the rectum and colon up to the ileocaecal valve.Typically, this procedure is performed with a CCD camera or a fibreoptic camera on a flexible tube passed through the anus.

The term “amnestic use” as used herein relates to the induction ofamnesia, which represents the partial or total loss of memory.

The term “operative procedure” as used herein refers to all kind ofmedical intervention into the living body, either invasive ornon-invasive, for diagnostic and/or therapeutic purposes. Medicalintervention in particular comprises medical treatments which, on aregular basis, are expected to cause post-operative pain for thepatient. As a synonymous term for “operative procedure” the term“surgery” is also used herein.

Manual or mechanical ventilation is defined as external assistance inbreathing by manual or mechanical methods such as e.g. mask ventilation,or intubation.

The phrase “pharmaceutically acceptable salt” refers to a salt ofvariable stoichiometry formed by compound of formula (I) and a counterion and which is physiologically tolerable and/or do not typicallyproduce an allergic or similar untoward reaction, such as gastric upset,dizziness and the like, when administered to a mammal.

As used herein, the term “solvate” refers to a complex of variablestoichiometry formed by a solute (in this invention, a compound offormula (I), an opioid or a salt thereof) and a solvent. Such solventsfor the purpose of the invention may not interfere with the biologicalactivity of the solute. Examples of suitable solvents include, but arenot limited to water, methanol, ethanol and acetic acid. Preferably thesolvent used is a pharmaceutically acceptable solvent. Examples ofsuitable pharmaceutically acceptable solvents include water, ethanol andacetic acid. Most preferably the solvent used is water.

DETAILED DESCRIPTION OF THE INVENTION

The invention relates to the ultra-short-acting benzodiazepine CNS 7056or a pharmaceutically acceptable salt or solvate thereof for inductionof sedation, whereas CNS 7056 is administered in combination with anopioid. Preferably both drugs are given intravenously. Moreover, bothdrugs are preferably administered in a fixed dose. The dose of CNS 7056can vary between about 2 to about 10 mg, preferably between about 3 (or4) mg and about 9 mg, and most preferably between about 5 and about 8mg. In a particular embodiment of the invention 10 mg CNS7056 isadministered.

Thus, it has been found out that a fixed dose determined from theputative drug exposure and clearance provides a safe and effective dose,especially in the context of the above claimed dosing regimen.

In one embodiment of the invention CNS7056 is administered as a bolusinjection with a concentration of CNS 7056 of 1 mg/ml.

In a preferred embodiment of the invention at least one further top-updose of CNS 7056 follows the initial dose of CNS 7056. The top-up doseis between around 1.5 and around 4 mg, preferably between around 2 andaround 3, and most preferably 2 or 3 mg.

In a preferred aspect of the invention, CNS 7056 is administered in afixed dose, whereas the initial dose and the top-up doses are combinedas follows:

8 mg initial dose plus 2 or 3 mg top-up dose, or7 mg initial dose plus 2 or 3 mg top-up dose, or5 mg initial dose plus 2 or 3 mg top-up dose4 mg initial dose plus 2 or 3 mg top-up dose or3 mg initial dose plus 2 or 3 mg top-up dose.

In a particular embodiment the initial dose and the top-up(s) areselected to provide a maximum dose of 10 mg per treatment.

In a further preferred aspect of the invention, CNS 7056 is administeredin a fixed dose, whereas the initial dose and the top-up doses arecombined as follows:

8 mg initial dose plus 3 mg top-up dose, or7 mg initial dose plus 2 mg top-up dose, or5 mg initial dose plus 3 mg top-up dose.

In one aspect of the invention the patients receive an initial singleintravenous dose of CNS 7056 over one minute.

In another aspect of the invention the CNS 7056 top-up dose isadministered not less than 2, preferably 3 minutes and more preferably 4minutes apart from the starting or the previous top up dose.

In one aspect of the invention up to a maximum of six top-up doses ofCNS 7056 are given, so that not more than seven doses of CNS 7056 aregiven per treatment. However, it was found out by the inventors thatwith an initial dose of up to 10 mg—if at all—only 1 to 3, preferablynot more than 2, top up doses are needed. Thus in one aspect of theinvention the number of top ups is below 3, preferably even below 2.

The medical treatment—and thus the required sedation according to theinvention—preferably lasts less than one hour, preferably less than 45minutes and more preferably less than 30 minutes.

According to the invention the top-up doses can contain the identical ora different amount of CNS 7056, whereas the use of identical amounts ofCNS 7056 is preferred.

In another aspect of the invention the dosing regimen is adjusted inorder to maintain a MOAA/S score of not more than 4 (including 4),preferably of 1 to 4, and more preferably of 2 to 4. This adjustment ispreferably performed by alteration of the top-up doses with regard tothe dose of the top-up dose or the time interval between the top-updoses or both. In a further preferred aspect of the invention a changein the time interval between the top-up doses is used for maintainingthe level of the MOAA/S score. Hereby, the time interval is shortened incase that the patient exhibits reduced sedation and prolonged in case ofincreased sedation.

In a further aspect of the invention the dosing regimen is adjusted inorder to induce and/or maintain a mild to moderate sedation, which maybe assessed by the MOAA/S and categorized by the following scheme:

Level of sedation MOAA/S score Fully alert 5 Mild sedation 4 Moderatesedation 2-3 Deep sedation 0-1 Loss of consciousness 0

In one embodiment the sedation profile of the invention is preferablycharacterized by:

MOAA/S≦4 at three consecutive measurements, e.g. taken every minuteno requirement for a further sedative (e.g. a rescue sedative)no manual or mechanical ventilation

Hence in one embodiment the invention relates to the use of CNS7056 incombination with an opioid (e.g. fentanyl) without a mechanical ormanual ventilation of the patient. Nevertheless supplemental oxygensupply is possible.

In a further aspect of the invention CNS 7056 is administered as a fixeddose per patient. This dosing strategy is based on an extensive PK/PDanalysis which revealed that the body weight was not a statisticallysignificant predictor of the systemic clearance or exposure of CNS 7056and so dosing in units of mg/kg offers no advantage in terms of safetyor efficacy.

In another aspect of the invention CNS 7056 is given to adult patients,i.e. which are 18 years or older.

Methods for preparation of CNS 7056 together with pharmaceuticallyacceptable forms are described in EP application EP 1 183 243 B1.Suitable forms for use in pharmaceutical compositions are also describedtherein. This document is incorporated by reference as to the disclosureof the manufacture of pharmaceutically acceptable forms of CNS 7056.

The compound CNS 7056 can be used as free base form or as apharmaceutically acceptable salt. As a preferred salt the besylate oresylate salt of CNS 7056 can be used. The besylate and esylate salts ofCNS 7056 are described by the PCT applications WO 2008/007071 and WO2008/007081, respectively. These salts as disclosed therein areincorporated by reference.

In a further preferred aspect of the invention the besylate salt of CNS7056 is used in one of the polymorphic salt forms 1, 2, 3 or 4 asdescribed by PCT application WO 2008/007071. These polymorphic forms asdisclosed therein are fully incorporated by reference.

In another aspect of the invention the esylate salt of CNS 7056 is usedin the polymorphic salt form 1 or 2 as described by PCT application WO2008/007081. These polymorphic forma as disclosed therein are fullyincorporated by reference.

According to the invention the ultra short-acting benzodiazepine CNS7056 is administered as an intravenous (IV) bolus application,preferably as IV bolus of less than 1 minute, more preferably less than30 seconds and most preferably of approximately 15 seconds, which isequivalent to a manual application of an intravenous drug.

In one aspect of the invention the opioid drug is preferably selectedfrom the group consisting of:

morphine, codeine, thebain, papaverin, narcotine,heroin, hydromorphone, dihydrocodeine, thebacon, hydrocodone,oxymorphone, oxycodone, ketobemidone, pethidine, anileridine,piminodine, phenoperidine, furethidine, [alpha]-prodin, trimeperidine,meptazinol, profadol, methadone, dextromoramide, levomethadyl acetate,phenadoxone, dipipanone, themalon, dextropropoxyphene,N-methylmorphinan, levorphanol, dextrometorphane, butorphanol,pentazocine, phenazocine, ketocyclazocine, bremazocine, sufentanil,carfentanil, fentanyl, lofentanil, alfentanil, ohmefentanil,remifentanil, pitramide, benztriamide, diphenoxylate, loperamide,tramadol, tilidine, U-50488,1-benzyl-4-(4-bromo-phenyl)-4-dimethylamino-cyclohexanol;alfentanil, buprenorphine, butorphanol, codeine, dextromoramide,dextropropoxyphene, dezocine, diamorphine, dihydrocodeine,diphenoxylate, ethylmorphine, etorphine, hydrocodone, hydromorphone,ketobemidone, levomethadone, levomethadyl-acetate, levorphanol,meptazinol, morphine, nalbuphine, nalorphine, oxycodone, oxymorphone,pentazocine, pethidine, piritramide, remifentanil, sufentanil, tilidine,tramadol, tapentadol, met-enkephalin, leu-enkephalin, nociceptin,β-endorphin, endomorphin-1, endomorphin-2, metorphamid, dynorphin-A,dynorphin-B, or α-neoendorphin.

The analgesic drug is administered preferably as an intravenous bolusapplication.

In a more preferred aspect of the invention the patient is given afentanyl analogue according to formula (II):

wherein

R₁ is H, F, Cl, Br, or J;

R₂ is C₁-C₄ alkyl;

R₃ is H, CH₂—O—(CH₂)_(n)—CH₃ with n=0-3, or COOR₈ with R₈=C₁-C₄ alkyl;

R₄ is H, C₁-C₄ alkyl;

R₅ is H, —OH, C₁-C₄ alkyl;

R₆ is H, —OH;

R₇ is Aryl, heteroaryl or COOR₈.

In a most preferred aspect of the invention the patient is given afentanyl analogue selected from the group consisting of fentanyl,alfentanil, carfentanil, lofentanil, remifentanil, sufentanil,thiofentanyl, α-methylthiofentanyl, α-methylacetylfentanyl,α-methylfentanyl, ohmefentanyl, β-hydroxy-fentanyl, parafluorfentanyl,3-methylfentanyl or a salt or a solvate thereof.

These fentanyl analogues are defined by a structure of formula (II)wherein the residues R₁ to R₇ are given as follows:

Substance R₁ R₂ R₃ R₄ R₅ R₆ R₇ fentanyl —H —CH₂CH₃ —H —H —H —H -phenylalfentanil —H —CH₂CH₃ —CH₂OCH₃ —H —H —H 4-ethyl-5-oxo-1,4-dihydrotetrazol-1- yl carfentanil —H —CH₂CH₃ —COOCH₃ —H —H —H -phenyllofentanil —H —CH₂CH₃ —COOCH₃ —CH₃ —H —H -phenyl remifentanil —H —CH₂CH₃—COOCH₃ —H —H —H —COOCH₃ sufentanil —H —CH₂CH₃ —CH₂OCH₃ —H —H —H2-thienyl thiofentanyl —H —CH₂CH₃ —H —H —H —H 2-thienyl α-methylthio- —H—CH₂CH₃ —H —H —CH₃ —H 2-thienyl fentanyl α-methyl- —H —CH₃ —H —H —CH₃ —H-phenyl acetylfentanyl α-methylfentanyl —H —CH₂CH₃ —H —H —CH₃ —H -phenylohmefentanyl —H —CH₂CH₃ —H —CH₃ —CH₃ —OH -phenyl β-hydroxyfentany —H—CH₂CH₃ —H —H —H —OH -phenyl parafluorfentanyl p-F —CH₂CH₃ —H —H —H —H-phenyl 3-methylfentanyl —H —CH₂CH₃ —H —CH₃ —H —H -phenyl

In a particular preferred aspect of the invention the patient is givenfentanyl or a pharmaceutically acceptable salt or solvate thereof.

The results of the PK/PD analysis revealed a pharmacodynamic interactionbetween fentanyl and CNS 7056 when the application of fentanyl waswithin 5 to 10 minutes prior to the initial administration of CNS 7056.This interaction between fentanyl is also supported by the results ofthe clinical study CNS 7056-002, in which CNS 7056 was applied incombination with fentanyl, as in this study lower doses of CNS 7056 ledto a suitable sedation as compared to the studies CNS 7056-001 and CNS7056-003, in which CNS 7056 was applied as a single agent (see FIG. 1Aversus FIG. 1B). The doses which led to sufficient sedation to performthe procedure (i.e. MOAA/S below or equal 4) in study CNS 7056-002 in 64to 100% of subjects ranged from 0.04 mg/kg to 0.1 mg/kg of CNS 7056 plustop up doses of 0.04 mg/kg in addition to 50 mcg of fentanyl in order tokeep the sedation for a period of 30 minutes. In study CNS 7056-003single doses of CNS 7056 of 0.1 mg/kg to 0.2 mg/kg without concomitantfentanyl led to sufficient sedation in 32-64% of patients. This supportsa safe use of fentanyl in combination with CNS7056.

A sufficient analgesic coverage as provided by fentanyl reduces also therequirement of top-up doses of CNS 7056, resulting in a more stablesituation for mild to moderate sedation and avoiding frequent drops toMOAA/S levels of 0.

In one aspect of the invention the fentanyl that is given in a fixeddose regimen, is preferably between 50 to 200 mcg/patient, morepreferably between 75 and 150 mcg/patient and most preferably 100mcg/patient.

As mentioned above the results of the PK/PD analysis found no evidencefor a pharmacodynamic interaction between fentanyl and CNS 7056. Thislack of PD interaction allows administration of fentanyl in a broad doserange, as claimed herein. This rather high dose of fentanyl, especiallywhen given shortly before the start of the diagnostic or therapeuticintervention, results in a maximum analgesic coverage at the start ofthe diagnostic or therapeutic intervention.

In a most preferred aspect of the invention, 100 mcg of fentanyl isgiven immediately before or together with the initial fixed dose of CNS7056.

In a further aspect of the invention the fentanyl is administered notearlier than 10 minutes before administration of CNS 7056, preferablywithin at least 5 minutes prior to CNS 7056 administration, morepreferably within at least 3 minutes prior to CNS 7056 administrationand most preferably together with CNS 7056.

The short time interval between fentanyl dosing and CNS 7056 results ina maximum analgesic coverage at the start of the diagnostic ortherapeutic intervention. This is important for procedures that startwith painful interventions. As an example in colonoscopy the insertionof the scope and its movement through the sigmoid curve of the colon atthe beginning is the most inconvenient and painful part of theprocedure.

In one aspect of the invention at least one additional (top-up) dose offentanyl is given, preferably in the range of 10 to 100 mcg/patient,more preferably in the range of 10 to 75 mcg/patient and most preferably25 mcg/patient.

In a further aspect of the invention the time interval between the firstfentanyl dose and the top-up dose and/or between two top-up doses is inthe range between 2 to 10 minutes,

In another aspect of the invention CNS 7056 is used for preoperativesedation, anmestic use for perioperative events, or conscious sedationduring short diagnostic, operative or endoscopic procedures.

In another aspect of the invention CNS7056 as of the invention is usedfor short procedures such as limb resetting or wound dressing.

In a preferred aspect of the invention CNS 7056 is used foranalgosedation.

In another aspect of the invention the use of CNS 7056 iscontraindicated for subjects with known hypersensitivity tobenzodiazepines and subjects with acute narrow-angle glaucoma. CNS 7056may be used in patients with open-angle glaucoma only if they arereceiving appropriate therapy.

In another embodiment the invention CNS7056 is provided in a containerfor pharmaceutical use comprising 10 mg of CNS7056, preferably in aconcentration of 1 mg/ml, e.g. a vial, ampoule, syringe or the like. Thecontainer comprising 10 mg CNS7056 preferably constitutes a drugproduct, preferably a ready-to-use drug product.

In a further aspect of the invention the pharmacological effect of theultra short-acting benzodiazepine CNS 7056 and/or the opioid drug can bereversed by another drug, which is referred to as a “reversal agent”.

As reversal drug for the ultra short-acting benzodiazepine CNS 7056 aGABA receptor antagonist is used, which is preferably flumenazil.

As reversal drug for the opioid drug an opioid receptor antagonist isused, preferably naloxone.

Example 1

The principal objectives of the analysis were to fit pharmacokinetic andpharmacodynamic (especially Modified Observer's Assessment ofAlertness/Sedation (MOAA/S) scores) models to the data obtained from thestudies CNS 7056-001 and CNS 7056-002 and use the parameters obtained tosimulate the results of different dosing regimens in order to predict anoptimal dose regimen for CNS 7056. Secondary objective was to explorethe pharmacodynamic interaction between CNS 7056 and fentanyl duringStudy CNS 7056-002.

Materials and Methods Study CNS 7056-001

Pharmacokinetic data were obtained after CNS 7056 had been administeredby intravenous infusion over one minute to groups of healthy volunteersat the following doses: 0.01, 0.025, 0.05, 0.075, 0.1, 0.15, 0.2, 0.25and 0.3 mg/kg. Both arterial (1, 2, 3, 4, 6, 8, 10, 12, 15, 20, 30, 45minutes and 1, 2, 3, 4 hours post-dose) and venous (2, 3, 4, 6, 8, 12hours) blood samples containing CNS 7056 and its metabolite, CNS 7054,were obtained from indwelling catheters. Concentrations of CNS 7056 andCNS 7054 were measured using HPLC with tandem mass spectrometricdetection. Measurements of sedation (MOAA/S and Bispectral Index (BIS)scores) and systolic and diastolic blood pressure were made at regularintervals.

Study CNS 7056-002

In the second part of the study, all subjects received a 50 mcgintravenous dose of fentanyl followed by a further 25 mcg if the initialpain relief was inadequate. Three cohorts of 15 patients were givenloading doses of CNS 7056 at 0.04, 0.075 or 0.1 mg/kg with the higherdoses only being administered once the safety of the lower doses hadbeen assessed. Up to a maximum of two supplemental, 0.04 mg/kg doses ofCNS 7056 were administered, not less than two minutes apart to obtainadequate sedation (MOAA/S≦3) for insertion of the colonoscope. Further0.04 mg/kg doses of CNS 7056 were administered during the procedure, noearlier than two minutes after the previous dose, in order to maintain aMOAA/S level of 4 for 30 minutes; no more than seven doses (the initialand six top-up doses) could be administered to any subject. The genderratio in each cohort was 7:8. Venous plasma levels of CNS 7056 weremeasured at 1, 5, 10, 20 and 30 minutes and at 1, 2, 4, 6, 8, 12 and 24hours post-dose.

Analysis

Physiologically-based three- and four-compartment pharmacokinetic modelswere fitted to the arterial and venous plasma levels of CNS 7056 fromthe combined data obtained in Studies CNS 7056-001 and CNS 7056-002using the non-linear modelling programme, NONMEM. The possible influenceof body weight, sex and heart rate on volumes and clearances wasexamined by covariate analysis. The derived pharmacokinetic parametersfrom the preferred models were then used to simulate the arterialconcentrations of the drug at the time points at which pharmacodynamicdata, MOAA/S scores and blood pressures, were obtained and sigmoidinhibitory pharmacodynamic models fitted to the observations via a“link” model, again using NONMEM. A number of sudden, apparently random,increases in MOAA/S score of short duration were identified within thedata-set and attributed to external stimuli such as acute pain from thecolonoscope or treatment by the nursing staff; these were modelled bythe introduction of a covariate which increased EC50. Another covariate,the “scoping-factor” which also increased EC50, was added to the modelin order to simulate reduced sedation during the actual colonoscopyprocedure caused by general irritation. As no concentrations of fentanylwere obtained during Study CNS 7056-002, historical values of clearancesand volumes of distribution were used in order to simulate plasma levelsof the opioid so that pharmacodynamic models of hypotension andinteraction with CNS 7056 could be developed. The interaction model ofsedation introduced a covariate, estimated by the modelling, whichconverted simulated plasma levels of fentanyl into concentrations of CNS7056 at the effect site.

Population Pharmacokinetic Analysis

A sequential population approach was employed, first estimating thepharmacokinetic parameters for CNS 7056 and then using these results toobtain the corresponding pharmacodynamic parameters. A non-linear,mixed-effect modelling programme (NONMEM, version 6) was applied to thedata using the first order conditional estimation with interactionmethod (FOCE-I). Physiologically-based pharmacokinetic models werefitted to a combination of arterial and venous plasma levels of CNS 7056from the combined CNS 7056-001 and CNS 7056-002 data sets (FIG. 2),using the ADVAN6 sub-programme, with tolerance (TOL) set to five, tosolve the differential equations. All the models contained a centralcompartment corresponding to the venous system and other highly perfusedtissues, arterial, pulmonary, peripheral and deep compartments.Clearance of CNS 7056 to CNS 7054 was assumed to take place from thecentral, pulmonary or peripheral compartments, or from a hepatic one(FIG. 2). A combination of two clearance compartments was alsoinvestigated. An additional “deeper” compartment was introduced asmodels with four-compartments had been shown to be superior to thosewith three in study CNS 7056-001. Since the erythrocyte penetration ofCNS 7056 was not known, cardiac output of blood/plasma was estimatedduring the modelling process.

Results Population Pharmacokinetic Analysis of CNS 7056

Modelling of the arterial plasma levels of CNS 7056 in Study CNS7056-001 found that, although a three-compartment model fitted the datawell, the corresponding four-compartment model, with systemic clearancefrom the central compartment, gave a considerably smaller objectivefunction. In addition, when clearance was assumed to have taken place inthe peripheral compartment, there was a further substantial drop inobjective function.

The simplest physiologically-based pharmacokinetic models, therefore,contained three compartments of unknown volume plus arterial andpulmonary compartments whose volumes (arteries=0.65 kg/70 kg, lungs=1.0kg/70 kg) were assumed to be proportional to body weight. Systemicclearance and the two inter-tissue clearances were also unknown. Sincethe erythrocyte penetration of CNS 7056 was not known, cardiac output ofblood/plasma also had to be estimated during the modelling process.

This model was expanded to one with four compartments of unknown volumeand the site of clearance allowed to be the central, peripheral,pulmonary or an additional hepatic compartment, whose volume (1.5 kg/70kg) and relative blood flow (26% of cardiac output) were assumed to bethose of a standard subject. Inter-individual variability (IIV or Eta)was included for systemic clearance, central, peripheral and deepvolumes of distribution in all models, together with proportional andadditive residual errors. A fifth Eta, on the volume of the fourthcompartment, was also investigated with each model.

Of the simple, three-compartment models, that with clearance from thelung (Run 128S) was clearly the best. Among the four-compartment modelswith dual clearance, the Run 144S with clearance from both the lung andliver proved to be the best one in terms of lowest objective function. Acomparison of the parameters from the better physiologically-basedpharmacokinetic models is shown in Table 1.

Covariate Analysis of the Population Pharmacokinetic Analysis of CNS7056

Body Weight does not Predict Clearance, Volumes or Blood Flow

Inter-individual variability on cardiac output and a limited covariateanalysis was undertaken based on the three-compartment model Run 128Swith pulmonary clearance of CNS 7056. When body-weight was considered asa predictor of clearance (Run 137S), volumes (Runs 130S, 152S, 153S) orblood flow (Run 127S) the objective function was essentially unchanged;in this case final minimisation did not occur (Table 2).

The absence of an influence of body-weight on the clearance of CNS 7056,shown by the insignificant change in objective function when thecovariate was introduced (Run 137S, Table 2), was also demonstrated byplotting body-weight against the fitted values of pulmonary clearance,using the results of Run 128S (FIG. 3), the slope of the linearregression equaling 0.1 with an R² of 0.0155.

Conclusion: As no relationship was found between body weight andsystemic clearance (FIG. 3), there is no advantage in dosing by weightin terms of consistency of exposure to CNS 7056.

Population Pharmacodynamic Analysis

Continuous pharmacodynamic models were fitted to the MOAA/S data, eventhough these were categorical, because they are more stable when thereare several categories and because the results are more readilyinterpreted. Simple sigmoid inhibition pharmaco-dynamic models fittedthe MOAA/S data poorly and it was found necessary to modify the data-setin order that the observed scores could be accurately fitted. One- andtwo-minute “spikes” of increased MOAAS/S score were identified withinthe data-set and modelled as increases in EC₅₀ of approximately 30%. Theunexpected result that the efficacy of CNS 7056, expressed as thetypical EC₅₀, was the same in Study CNS 7056-001 (healthy volunteers)and CNS 7056-002 (patients undergoing a colonoscopy) was rationalised byassuming that residual sedation from the pre-operative dose of fentanylwas roughly nullified by general irritation throughout the procedure. A“scoping-factor”, which typically caused a 10-12% increase in EC₅₀, wasintroduced to account for this.

MOAA/S Pharmacodynamic Analysis of CNS 7056

All MOAA/S data from Studies CNS 7056-001 and CNS 7056-002 were used forthe pharmacodynamic modelling of sedation. Arterial plasma levelscalculated from the pharmacokinetic parameters estimated previously frommodel CNS 7056 PBPK128S were linked to an inhibitory sigmoid effectpharmacodynamic model of sedation via a hypothetical “effect” site and adelay rate constant “ke0”. E_(MIN) was set to zero and E_(MAX) to fivefor the basic MOAA/S models and IIV included for the threepharmacodynamic parameters, EC₅₀, ke0 and Hill coefficient, γ. Since thebasic models minimised with a singular R-matrix, the control files ofall subsequent MOAA/S models, were amended to include the MATRIX=Scommand in order that the covariance step could be performed.

The data-sets from Studies CNS 7056-001 and CNS 7056-002 were analysedseparately and then after being combined (Table 3). All of theparameters were estimated with good precision (average RSE %: 5.4-7.9%)and IIV of approximately 40% for all three pharmacodynamic parameters(Table 3). There were no obvious differences between the threepharmacodynamic parameters with EC₅₀ and ke0 from the individual studiesbeing within about 10% (Table 3). The combined data set “MOAASALL01S”was used for the subsequent pharmacodynamic modelling.

Covariate Analysis of Fentanyl as a Predictor of Sensitivity to CNS 7056

Although the pharmacodynamic parameters of the MOAA/S models fromStudies CNS 7056-001 and CNS 7056-002 were similar, the possible effectof fentanyl, used only in the second study, was investigated (Table 4).The first model (MOAASALL05S) assumed that EC₅₀ was different in thepresence of fentanyl, but the value obtained (0.338 mcg/ml) was verysimilar to that in its absence (0.364 mcg/ml) and the decrease inobjective function compared to model MOAASALL01S, which assumed that thetypical value of EC₅₀ was unaffected by fentanyl, was insignificant(ΔOFV=−0.85, Table 4). When the actual dose of fentanyl (0, 50, or 75mcg) was taken into account (model MOAASALL09S), the decrease inobjective function was again minimal (ΔOFV=−1.73, Table 4).

CNS 7056-Fentanyl Interaction MOAA/S Analysis

The use of covariate analysis to examine a possible pharmacodynamicinteraction between fentanyl and CNS 7056 assumes a constant effectthroughout the observation period. However, fentanyl was given a 5-10minutes before CNS 7056 and, as its clearance is quite rapid,concentrations towards the end of the procedure are likely to have beenrelatively low. Accordingly, historical data (Table 5) were used tosimulate appropriate plasma levels of fentanyl and these were assumed tobe reflected as equivalent concentrations of CNS 7056 at the effect sitevia an equivalence parameter. The correct times of the later MOAA/Sscores were used in all the models of the CNS 7056-Fentanyl interaction.

When a fentanyl effect was added to the basic model, the equivalencefactor was very small and slightly negative (−4.46) and there was nosignificant change in objective function (Runs FEN01AS and FEN03S, Table6). However, when allowance was made for the pain associated withcolonoscopy, there was a significant decrease in objective function (RunFEN05S, ΔOFV=−67.6, Table 6) and a larger, positiveconcentration-equivalence factor of 21.5. In addition the effectattributed to the colonoscope in reducing sedation (i.e. increasingEC₅₀) rose from 11.6% to 14.5% (Runs FEN04S and FEN05S, Table 6).Allowance for inter-subject variability in the pharmacodynamicinteraction further reduced the objective function by 35 (Runs FEN06S,FEN05S), although the inter-subject variability was large at 162% andpoorly estimated (Table 6).

As the systemic clearances of fentanyl and CNS 7056 are comparable atroughly 60 I/h (Table 5), the relative systemic exposures areessentially proportional to the ratio of their respective doses. Thusfor typical single doses of CNS 7056 and fentanyl of 7 and 0.05 mg,respectively, systemic exposure would be approximately 0.12 and 0.00083mcg·h/ml for the two drugs. An equivalence factor of 20 would,therefore, raise the apparent exposure of fentanyl to 0.017 mcg·h/ml,14% of that of CNS 7056.

The effects of sudden additional stimuli were introduced into thefentanyl-interaction model with similar results (Table 7) to those withthe simpler model (Table 8, Table 9). Thus one and one/two minutestimuli gave rise to reductions in objective function of 237 (RunFEN07S) and 351 (Run FEN08S), respectively, compared to 253 and 371 forthe simpler model (Runs MOAASALL21 and MOAASALL23, Table 8). Combiningthe effects of the colonoscope and additional stimuli on EC₅₀ alsoreduced the objective functions (Runs FEN09S, FEN05S: ΔOFV=363, Tables 6and 7) in a similar manner to the simpler models (Runs MOAASALL31 andMOAASALL18: ΔOFV=−352, Table 9).

Inter-subject variability had the least effect when applied to theadditional stimuli (Run FEN11S, ΔOFV=−21, Table 10) and the reductionsin objective function for the concentration-equivalence factor(ΔOFV=−63, Run FEN14S) and colonoscopy parameter (ΔOFV=−73, Run FEN18S)were similar. Combinations of these two produced the preferred model,Run FEN19S with an objective function of 2053.7 compared to the bestwithout any fentanyl effect of 2152.8 (MOAASALL32S, Table 9,ΔOFV=−99.1). A direct comparison between MOAASALL27S and Run FEN11S(OFV=2169.0) which had inter-individual variability (IIV) on the sameparameters, demonstrates an improvement in objective function of 24.5with the interaction model. As with the simpler modes, the data set wasmodified with the zero scores being changed to negative values. Theexact correspondence of the observed and fitted scores, after roundingto integer values, was 70% for the final fentanyl-interaction model with23% of the results differing by one. The model was further optimised inan analogous manner to the simpler model, as above, in order to maximisethe correspondence of the observed and modelled zero scores (Table 11).In this case the difference between the objective functions of thecorresponding models was 19 and 51, but increased to 221 by thesubstitution of IIV on the concentration-equivalence and scoping factorsfor E_(MIN) (Table 12). The interaction model assumed that fentanylconcentrations at the effect site were equivalent to those of CNS 7056after multiplication by a concentration-equivalence factor determined bythe modelling. The population mean of this factor was 28 (Table 13) andranged from 6 to 330 (Table 14). Bearing in mind that the typicalloading doses of CNS 7056 were roughly 100 times those of fentanyl(total doses 3-4 times as high) and that the clearances of the twocompounds are comparable, this indicates that fentanyl might contributein the order of a quarter of the sedation of the loading doses of CNS7056 (mean dose=5.5 mg) and 5-10% of the overall effect (mean totaldose=19.4 mg).

Pharmacodynamic Analysis Using the Monte Carlo Method

Monte-Carlo simulations were undertaken using the pharmacodynamicparameters from both the preferred simple and CNS 7056-fentanylinteraction models of MOAA/S score, varying the loading and top-up dosesand including a similar proportion of spikes of reduced MOAA/S score. Atotal of 1000 Monte Carlo simulations was carried out at a range ofdosing regimens likely to be appropriate for CNS 7056 (Table 15), usingthe pharmacodynamic parameters from Run MOAASALLMIN61S (Table 16). Thesimulations generated fractional MOAA/S scores which were rounded to thenearest integer, negative numbers being considered to be zero. Theresults of the modelling automatically assumed that all patients weretreated in the same way as those of Studies CNS 7056-001 and CNS7056-002 (i.e. no-fentanyl-no-colonoscopy or fentanyl (50 mcg or 75 mcg5-10 minutes before CNS 7056) plus colonoscopy). The following protocolwas followed:

-   -   Initial doses of CNS 7056 had to be sufficient to give adequate        sedation (MOAA/S Score of three or lower) to most subjects so        that the colonoscope could be inserted.    -   One or two top-up doses were allowed if the MOAA/S scores were        still above three. If these were insufficient the subject was        considered to be a drop-out.    -   Additional top-up doses up to a maximum total of six were        permitted to maintain sedation below a score of five for a        procedural length of 24 minutes from the first dose of CNS 7056.        Subjects whose MOAA/S score reached five within 24 minutes of        the first dose were considered to be failures.    -   MOAA/S scores of zero were to be avoided in as many subjects as        possible.    -   The minimum time interval between two doses was set at two        minutes.    -   Additional stimuli were randomly simulated at a comparable rate        (815/1000 subjects) to those observed in Studies CNS 7056-001        and CNS 7056-002, although no subject had more than four spikes        of pain.

The Monte Carlo pharmacodynamic simulations generated 1000 continuousMOAA/S curves for each dosing regimen and these were converted to scoresof zero to five and hence to four critical parameters which were eitherto be minimised (percentage zero scores, drop-outs, failures—i.e.subjects who were “scopable”, but whose sedation was not maintained for24 minutes with a maximum of six top-up doses) or maximised (percentage“scopable” after the loading dose of CNS 7056. The average number oftop-ups and, hence, the average total dose of CNS 7056 was alsocalculated.

The number of simulated drop-outs depended on both the fixed loading andfixed top-up doses; thus a rate of 5% would be expected after thefollowing dosage regimens: 9/2.5 mg, 8/3 mg, 7/3.5 mg, 6/4 mg and 5/4.5mg (FIG. 4). Similarly, 4%-5% zero scores were predicted to beassociated with 9/2.5 mg, 8/3 mg and 7/3.5 mg regimens. At the lower 5and 6 mg loading doses, the zero scores were only governed by the sizeof the top-ups, 4% following 3.5 mg doses (FIG. 4). The failure ratealso depended solely on the size of the top-ups; 5% being predicted tobe found by 3 mg doses (FIG. 4). The fraction of simulated subjectswhose MOAA/S score was below three after the loading dose of CNS 7056(i.e. they were considered to have undergone colonoscopy) was 90%, 83%,72%, 57% and 38% after doses of 9 mg, 8 mg, 7 mg, 6 mg and 5 mg,respectively.

The effect of varying the minimum time intervals between doses of CNS7056 was studied. Time intervals longer than the standard two minuteswould reduce the possibility of failures, patients becoming alert toosoon because the maximal permissible number of top-up doses had beentaken well before the end of the procedure. For example, the simulationsgave a 5% failure-rate on a 6/3 mg dosing regimen with a 2 minute timeinterval but only 0.2% with 4 minutes (Table 17). However, still longertime intervals increased the failure rate (Table 17). Longer timeintervals should also reduce the possibility of over-dosing (and, hence,increased fraction of zero scores) following a “spike” of reducedsedation after an additional stimulus. However, the simulations did notindicate that this was likely and there was no significant reduction inzero scores (Table 17). The danger of a patient becoming fully alertduring the procedure would, therefore, probably outweigh the reductionin failure rate. This definition of failure presupposes that theprocedure will last for a full 24 minutes; these subjects might not befailures if the colonoscopy were completed earlier or if one additionaltop-up were employed.

Pharmacodynamic Simulations Based on the CNS 7056-Fentanyl InteractionAnalysis

Simulations based on the CNS 7056-fentanyl interaction model gave asimilar proportion of drop-outs to the simpler model (e.g. 42‰ versus44‰ with a 6/4 mg dosing regimen, 50 mcg given four minutes before CNS7056, Table 18, Table 15), but the number of zero scores was greater(9.95% versus 6.46% with the same regimen). The proportion of “scopable”subjects after the loading dose was slightly higher (604‰ as opposed to567‰). However, the major difference was in the number of failures,subjects undergoing the procedure but reaching a MOAA/S score of fivewithin 24 minutes of the dose of CNS 7056 despite six top-up doses,(e.g. 86‰ versus 13‰ with a 6/4 mg dosing regimen). All of thesedifferences can be explained by the steeper concentration-response curveof the interaction model (typical Hill coefficients=5.16 and 4.03, Table19, Table 16).

Increasing the doses of fentanyl produced a dose-dependent increase inmaximal sedation when combined with a fixed dose of CNS 7056,approximately one MOAA/S unit per 50 mcg of the opioid (FIG. 5).Doubling a 50 mcg dose of fentanyl decreased the drop-out rate by about40% (e.g. from 9.3% to 5.7% with a 6/3 mg dosing regimen) but increasedthe number of zero MOAA/S scores by about 40% (FIG. 6, Table 18). Thesame change in fentanyl dose increased the fraction of subjects“scopable” after the loading dose of CNS 7056 by 5-50% depending on thedose of CNS 7056 (FIG. 6, Table 18), but did not influence the failurerate.

The effect of the CNS 7056-fentanyl interaction was not stronglyinfluenced by the time interval between administration of the twocompounds, time intervals of 0-7 minutes giving comparable results interms of maximal sedation and number of zero scores, drop-outs andfailures (FIG. 7, Table 20). Overall, the 8/3 mg dosing regimen wouldappear to be optimal as the simulations indicate a high proportion ofscopable subjects after the loading dose and drop-outs, failures andzero scores all of 5% or less (Table 18, Table 21).

Summary

A data-set consisting of the predominantly arterial CNS 7056 plasmalevels from Study CNS 7056-001 has been combined with one made up of thevenous concentrations from Study CNS 7056-002 in order that the arteriallevels needed for population pharmacodynamic models could be simulatedfor the latter study.

Physiologically-based pharmacokinetic models with three or fourcompartments of unknown volume plus pulmonary and arterial compartments,whose volumes were assumed to be proportional to body weight, werefitted to these data.

The modelling indicated that the lung was the primary metabolic organfor CNS 7056 with the liver possibly contributing as little as 10% ofthe drug's clearance. The pulmonary extraction ratio, and first-passmetabolism, was estimated to be approximately 28%.

Body weight was not a statistically significant predictor of thesystemic clearance of CNS 7056 and so dosing in units of mg/kg offers noadvantage in terms of consistency of exposure to CNS 7056.

Continuous pharmacodynamic models of MOAA/S scores were fitted to theobserved data. The first, simpler model was fitted directly to the rawdata and any effects of differences in fentanyl dosing regimens wereincorporated into the pharmacodynamic parameters. The second modelsimulated fentanyl concentrations, using the same historicalpharmacokinetic parameters for all subjects, and was able to estimatethe pharmacodynamic interaction between CNS 7056 and fentanyl. A 50 mcgdose of fentanyl typically contributed about 5-10% of the sedativeeffect of a 20 mg total dose of CNS 7056, integrated over the wholeprocedure. The acute effect was larger, a 50 mcg dose being responsiblefor an additional maximal fall in MOAA/S score of roughly one unit whencombined with CNS 7056.

Both models were refined by the introduction of a “scoping factor”,which increased EC50, and described the reduction in sedation resultingfrom the presence of a colonoscope and a “pain factor”, which alsoincreased EC50, and corresponded to sudden “spikes” of increased MOAA/Sscore.

Despite large improvements in the quality of the models with thesemodifications, shown by reductions in objective function of severalhundred, the observed zero MOAA/S scores were still poorly fitted. Thisdefect was resolved by modifying the zero scores in the data-set tonegative values (−1.25 or −1.3). The exact correspondence of theobserved and fitted scores was 70% for the final fentanyl-interactionmodel with 23% of the results differing by one.

The CNS 7056-fentanyl interaction model fitted the observed datasignificantly better than the simpler model (ΔOFV˜−30). However, itsmajor advantage resulted from its ability to include inter-subjectvariability in both of the highly variable scoping andconcentration-equivalence factors (ΔOFV˜−200).

Monte Carlo simulations of a wide range of dosing regimens suggestedthat a loading dose of 8 mg of CNS 7056 plus 100 mcg of fentanyl,followed by 3 mg top-up doses at intervals of no less than 2 minutes,would be optimal in terms of minimising drop-outs, MOAA/S scores of zeroand failures (subjects whose sedation was not maintained satisfactorilyfor 24 minutes with 6 top-ups) and maximising the number suitable forinsertion of the colonoscope after the loading dose of CNS 7056.

Provided it was not large, the time interval between fentanyl and CNS7056 dosage made little difference to the simulations, which indicatedthat the loading dose of CNS 7056 could be given at any time betweenthat of fentanyl and 6-7 minutes later.

Example 2: Phase IIb Study of Remimazolam Vs. Midazolam in UsingCombination Fixed Doses Study Design

The Phase IIb trial was a double-blind, randomized, parallel group studyexamining three dose regimens of Remimazolam (CNS 7056) compared withMidazolam in 160 patients undergoing a colonoscopy. The patientsreceived either one of three different initial doses of Remimazolam orMidazolam followed by “top-ups” (i.e. multiple doses) as required tomaintain an adequate sedation level to undergo a standard colonoscopyprocedure.

The study—conducted in multiple sites in the U.S.—was designed toevaluate the safety of Remimazolam and the success of the sedation, thetime to peak sedation as well as the time to full recovery anddischarge, in comparison to the gold-standard agent, Midazolam. Inaddition, based on the results of the successfully concluded Phase Iband IIa studies, this study was designed to further refine the optimaldose regimen before moving into Phase III.

The following data are based on the ITT (intent to treat) analysis only:

The patients received one of the following doses of Midazolam orRemimazolam:

-   -   Midazolam—2.5 mg with 1.0 mg top-ups (40 patients)    -   Remimazolam—8.0 mg with 3.0 mg top-ups (40 patients)    -   Remimazolam—7.0 mg with 2.0 mg top-ups (40 patients)    -   Remimazolam—5.0 mg with 3.0 mg top-ups (40 patients)

The dose of Midazolam was selected as representing the labeled dose. Thedoses of Remimazolam were selected based on the findings of the threeprevious clinical trials as predicted by the comprehensive PK/PDanalysis (see Example 1).

Results

The success of the procedure was a composite endpoint consisting ofsedation sufficient to initiate and complete the procedure, nomechanical or manual ventilation and no rescue sedation. The successrate (ITT) with Midazolam was 75%. The success rate with Remimazolam was97.5% at the lowest dose regimen, 95% at the middle and 92.5% at thehighest dose regimen. A rapid recovery to fully alert (13.3 minutes inthe lowest, 11.3 Minutes at the middle and 13.6 Minutes at the highestdose regimen) and short time to discharge (13.5 minutes in the lowest,14 minutes at the middle and 16.8 minutes at the highest dose regimen)were observed in all Remimazolam treated groups.

The time to fully alert was shorter in the Remimazolam groups whencompared to Midazolam. PAION's current interpretation is, that therelatively short wake up times of Midazolam are attributable to the factthat 25% of the midazolam patients did not respond to treatment andtherefore received Propofol as a rescue medication quite early which isknown as a very short acting compound. Therefore they did not receive“sufficient midazolam” to allow accumulation and resulting in a longeroffset times.

This is the first clinical trial with the optimised dose regimen showingclinically relevant improvements of Remimazolam over Midazolam.

Overall, the study showed that it is possible to achieve better resultswith Remimazolam as compared to the gold standard Midazolam. The safetyprofile observed in this trial confirmed the good tolerability alsoshown in all previous studies and as anticipated for a benzodiazepine.There were no unusual findings observed and no patient required manualor mechanical ventilation.

Overall, there was good cardiovascular and respiratory stability withRemimazolam treatment. Compared with the previous Phase Ib study theAESIs (adverse events of special interest) rate was substantially lowerdue to the revised dosing and study design according to the invention(10 related AESIs in 160 subjects in the Phase IIb study compared to 37in 45 subjects in the Phase Ib study).

Abbreviations

-   -   AUC Area Under the plasma concentration/time Curve    -   BIS Bispectral Index    -   Cl Clearance    -   Clhep Hepatic Clearance    -   Clpul Pulmonary Clearance    -   Clsys Systemic Clearance    -   CRF Case Report Form    -   ΔOFV Change in Objective Function Value    -   EC₅₀ Concentration leading to half Maximum Pharmacodynamic        Effect    -   E_(MAX) Maximum Pharmacodynamic Effect    -   E_(MIN) Minimum Pharmacodynamic Effect    -   ETA (η) NONMEM parameter for inter-individual variability    -   γ (Gamma) Hill Coefficient—Exponent for Concentrations and EC₅₀        in Pharmacodynamic Equation    -   HPLC High Performance Liquid Chromatography    -   ICU intensive care unit    -   IIV Inter-Individual Variability    -   ke0 Delay Rate Constant between Plasma and the Effect Site    -   Mm HG Millimetres of Mercury    -   MOAA/S Modified Observer's Assessment of Alertness and Sedation    -   MRT Mean Residence Time    -   OFV Objective Function Value    -   RSE % Percentage relative standard error    -   Q (Q2, Q3, Q4) Inter-Tissue Clearance    -   S.D. Standard Deviation    -   THETA NONMEM parameter    -   V1 Central Volume of Distribution    -   V2 (V3, V4) Peripheral Volume of Distribution    -   V_(SS) Steady-State Volume of Distribution

List of Tables

-   Table 1: Summary of Some Physiologically-Based Population    Pharmacokinetic Analyses of CNS 7056 (Studies CNS 7056-001 and CNS    7056-002)-   Table 2: Covariate Analysis of Three-Compartment Pharmacokinetic    Analysis of CNS 7056 (Run 128S)-   Table 3: Comparison of the MOAA/S Pharmacodynamic Models of Analyses    CNS 7056-001, CNS 7056-002 and the Combined Data sets-   Table 4: Covariate Analysis of the Effect of Fentanyl on EC₅₀ of CNS    7056 in the MOAA/S Pharmacodynamic Analysis.-   Table 5: Historical Pharmacokinetic parameters used for Simulations    of Fentanyl Plasma Levels.-   Table 6: Pharmacodynamic Interactions between Fentanyl and CNS 7056    in the MOAA/S Analyses (1).-   Table 7: Pharmacodynamic Interactions between Fentanyl and CNS 7056    in the MOAA/S Analyses (2)-   Table 8: Effect of the Period of Colonoscopy or Short-lasting    Additional Stimuli on EC₅₀ of CNS 7056 in the MOAA/S Pharmacodynamic    Analysis (1).-   Table 9: Effect of the Period of Colonoscopy and Short-lasting    Additional Stimuli on EC₅₀ of CNS 7056 in the MOAA/S Pharmacodynamic    Analysis (2)-   Table 10: Pharmacodynamic Interactions between Fentanyl and CNS 7056    in the MOAA/S Analysis (3)-   Table 11: Comparison of CNS 7056-Fentanyl Interaction    Pharmacodynamic Analyses in which the Observed MOAA/S “Zero” and    “Five” Scores were Modified-   Table 12: Comparison of the Three MOAA/S Analyses based on the same    Raw Data (Zero Scores changed to −1.30)-   Table 13: Comparison of CNS 7056-Fentanyl Interaction MOAA/S    Pharmacodynamic Analyses based on Three Pharmacokinetic Models-   Table 14: Descriptive Statistics of the Post-Hoc Calculated    Parameters of Final Fentanyl-Interaction MOAA/S Pharmacodynamic    Analysis for CNS 7056 (CNS 7056 FEN26S)-   Table 15: Summary of Monte Carlo Analyses of Various Dosing Regimens    of CNS 7056 (Based on Model MOAASALLMIN61S).-   Table 16: Summary of Pharmacokinetic and Pharmacodynamic Parameters    for CNS 7056 for Monte Carlo Analyses (CNS 7056PBPK128S,    MOAASALLMIN61S)-   Table 17: Summary of Monte Carlo Analyses of Two Dosing Regimens of    CNS 7056 with Varying Minimum time intervals between Top-up Doses    (Based on Model MOAASALLMIN61 S)-   Table 18: Summary of Monte Carlo Analyses of Various Dosing Regimens    of CNS 7056 and Fentanyl (Based on Fentanyl-Interaction Model CNS    7056FEN26S)-   Table 19: Summary of Pharmacokinetic and Pharmacodynamic Parameters    for CNS 7056 for Monte Carlo Analyses (CNS 7056PBPK128S, CNS 7056    FEN26S)-   Table 20: Summary of Monte Carlo Analyses of Various CNS    7056-Fentanyl Dosing time intervals (Based on Fentanyl-Interaction    Model CNS 7056FEN26S)-   Table 21: Summary of Monte Carlo Analyses of Three CNS 7056 Dosing    Regimens (Based on Fentanyl-Interaction Model CNS7056FEN26S)-   Table 22: Clinical Study (example 2): Superior Response Rate for    Remimazolam, (composite primary endpoint: MOAA/S≦4 on 3 consecutive    measurements AND completion of colonoscopy procedure AND no    requirement for alternative sedative or ventilation)-   Table 23: Clinical Study (example 2): Comparison of Success Rates in    Colonoscopy (ITT)-   Table 24: Clinical study (example 2): Shorter Time to Start of    Procedure and low Number of Top-ups-   Table 25: Clinical Study (example 2): Short Time to Fully Alert-   Table 26: Clinical Study (example 2): Short Time to Ready for    Discharge

LIST OF FIGURES

FIG. 1: Doses and success rates in studies CNS 7056-002 and CNS7056-003. Success was a composite of MOAA/S 4 on three consecutivemeasurements and completion of the procedure (including 30 minutessedation) and no requirement for alternative sedation or ventilation.

FIG. 2: Diagrammatic Representation of Physiologically-basedCompartmental Analyses of CNS 7056.

FIG. 3: Plot of Body-weight against Systemic (Pulmonary) Clearance ofCNS 7056 after Intravenous Administration at Various Doses (Model CNS7056PBPK128S.

FIG. 4: Comparison of Monte Carlo Simulated Proportion of Drop-outs,Failures and Zero MOAA/S Scores after Intravenous Administration of CNS7056 to 1000 Subjects (Based on Model MOAASALLMIN61S).

FIG. 5: Simulated MOAA/S Curves for a Typical Subject after VariousDoses of Fentanyl followed, 4 Minutes Later by 7 mg of CNS 7056 (Basedon Model MOAASALLFEN26S).

FIG. 6: Comparison of Monte Carlo Simulated Proportions of Drop-outs,Zero MOAA/S Scores and Subjects “Scopable” after Various DosingCombinations of Fentanyl and CNS 7056 (Top-up Doses kept constant at 3mg) to 1000 Subjects (Based on Fentanyl-Interaction Analysis CNS 7056FEN26)

FIG. 7: Simulated MOAA/S Curves for a Typical Subject after a 100 mcgDose of Fentanyl followed by 8 mg of CNS 7056 after Various Intervals(Based on Model MOAASALLFEN26S)

TABLE 1 Run Number 128S 135S 142S 144S Number of Individuals/Records99/1426 99/1426 99/1426 99/1426 Clearance Organ Lung Lung Lung/CentralLung/Liver Number of Compartments 3 4 3 4 Summary of Thetas and RSE%^(a) Blood/Plasma Cardiac Flow (l/h) 173 (3.37) 174 (3.59) 177 (3.54)175 (2.68) Pulmonary Clearance (l/h) 49.1 (2.02) 48.7 (2.00) 44.5 (6.11)45.0 (4.24) Central Volume (l) 1.71 (15.2) 1.24 (19.3) 1.93 (15.8) 0.834(15.8) Inter-Tissue Clearance(4) (l/h) 74.6 (3.29) 68.5 (5.45) 72.4(3.61) 46.2 (7.27) Inter-Tissue Clearance(5) (l/h) 25.7 (6.18) 42 (5.57)25.3 (6.16) 40 (5.12) Peripheral Volume(4) (l) 13.5 (9.18) 8.14 (12.8)13.4 (9.32) 6.47 (13.5) Deep Volume(5) (l) 23.4 (4.57) 23.8 (4.78) 23.1(4.58) 22.7 (5.28) Inter-Tissue Clearance(6) (l/h) 3.12 (13.2) 3.07(15.1) Deeper Volume(6) (l) 12 (20.4) 10.9 (16.7) Extra-pulmonaryClearance (l/h) 8.53 (52.4) 6.15 (49.7) Average Theta RSE % 6.27 9.7112.70 13.56 Summary of Etas and RSE %^(a) Pulmonary Clearance (%) 14.35(6.07) 14.42 (6.13) 17.12 (8.97) 16.22 (7.32) Central Volume (%) 146.9(52.9) 190.2 (66.8) 143.6 (52.2) 368.5 (105.) Peripheral Volume (%)50.10 (18.0) 71.40 (25.4) 50.48 (18.2) 90.06 (30.2) Deep Volume (%)22.55 (9.94) 23.44 (10.3) 22.59 (10.0) 24.10 (10.9) Average Eta (%)58.48 74.87 58.47 124.75 Average Eta RSE % 21.75 27.18 22.39 38.58Proportional Error (%) 21.81 (3.43) 21.03 (3.24) 21.74 (3.40) 20.98(3.17) Additive Error (±) (μg/ml) 0.122 (61.8) 0.111 (60.2) 0.123 (61.5)9.949 (66.5) Objective Function 8465.96 8355.34 8463.65 8338.55Objective Function - Baseline −110.62 −2.31 −127.40 Number ofEvaluations (Time 451 (0:4:4) 391 (0:4:13) 654 (0:5:26) 869 (0:17:57)Taken) Number of Significant Figures 6.80 6.50 4.70 6.30 Error MessagesNone None None None Maximum Eigenvalue ratio 65.99 18.08 94.42 130514.70^(a)Relative standard error (RSE %) Note: The compartmental volumes andclearances are numbered as follows: (1) = central, (2) = pulmonary, (3)= arterial, (4)= peripheral, (5)= deep, (6)= deeper, (7) = hepatic.

TABLE 2 Covariate/ Factor/ Objective Run Parameter Exponent (θ2)^(ab)Function (OFV) ΔOFV 128S 8465.96 — 126S η/Q — 8465.96 0.00 127S Weight/Q0.05 8465.92 −0.04 130S Weight/V1 2.98 8466.48 0.53 137S Weight/CL 0.1298464.20 −1.76 150S Sex/V1 −0.287 8483.68 17.72 152S Weight/V4 0.9648462.22 −3.74 153S Weight/V5 0.206 8465.29 −0.67 154S HR/V1^(c) 2.448447.20 −18.76 155S HR/Q^(c) −0.424 8452.71 −13.25 156S Age/V1 −0.478464.43 −1.53 157S HR2/V1^(c) 2.64 8451.65 −14.31 158S HR6/V1^(c) 2.538463.11 −2.84 159S HR/Q, V1^(c) −0.225/2.01 8445.74 −20.22^(a)Categorical Covariate - Parameter = θ1 × (1 − Category* θ2)(Category = 1 in males and 0 in females) ^(b)Continuous Covariate -Parameter = θ1 × (Covariate Value/Standard){circumflex over ( )} θ2(Standard Body-weight = 70 kg, Median age = 37 y, Median Heart-rates =64, 76, 72 bpm. for pre-dose, 2 minutes and 6 minutes, respectively)^(c)HR, HR2 and HR6 represent heart-rates taken pre-dose and 2 and 6minutes post-dose, respectively

TABLE 3 Summary file MOAAS001P01S MOAAS002P01S MOAASALL01S Number ofIndividuals/Records 54/1241 45/1523 99/2764 Summary of Thetas and (RSE%) EC₅₀ (μg/ml) 0.369 (7.91) 0.332 (5.18) 0.349 (4.35) Hill Coefficient(γ)  3.16 (8.82)  4.64 (8.81)  3.92 (6.76) E_(MIN)  0.0 (—)  0.0 (—) 0.0 (—) E_(MAX)  5.0 (—)  5.0 (—)  5.0 (—) ke0 (h⁻¹)  14.3 (6.97)  15.0(6.73)  14.8 (5.08) Average Theta RSE % 7.91 6.91  5.399 Summary of Etasand (RSE %) EC₅₀ (%) 49.98 (26.3) 27.92 (15.3) 36.02 (15.9) HillCoefficient (γ) (%) 44.94 (23.9) 38.31 (22.3) 54.49 (23.9) ke0 (%) 37.41(22.7) 34.91 (21.7) 35.23 (18.3) Average Eta 44.11  33.72  41.91 AverageEta RSE % 24.36  19.82  19.41 Additive Error (±) 0.408 (11.8) 1.140(15.5) 0.887 (9.26) Objective Function −655.81   2197.06   2641.12 Number of Evaluations (Time Taken)    216 (0:0:11)    165 (0:0:15)   197 (0:0:26) Number of Significant Figures 4.20 5.00 4.2 MaximumEigenvalue ratio 4.71 6.24  3.608

TABLE 4 Summary file MOAASALL01S MOAASALL05S MOAASALL09S Number ofIndividuals/Records 99/2764 99/2764 99/2764 Summary of Thetas and RSE %EC₅₀ (μg/ml) 0.349 (4.35) 0.364 (5.35)  0.38 (7.68) Hill Coefficient (γ) 3.92 (6.76)  3.9 (7.10)  3.93 (6.81) E_(MIN)  0.0 (—)  0.0 (—)  0.0 (—)E_(MAX)  5.0 (—)  5.0 (—)  5.0 (—) ke0 (h⁻¹)  14.8 (5.08)  14.8 (5.10) 14.9 (5.08) EC₅₀ with Fentanyl 0.338 (7.36) Effect of Fentanyl on EC₅₀(θ2)  −0.10 (89.4)^(a) Average THETA RSE %  5.399  6.232  26.741 Summaryof Etas and RSE % EC₅₀ (%) 36.02 (15.9) 35.70 (15.8) 35.54 (15.7) HillCoefficient (γ) (%) 54.49 (23.9) 54.72 (24.0) 54.72 (24.0) ke0 (%) 35.23(18.3) 35.07 (18.5) 35.07 (18.5) Average Eta (%) 41.91 41.84 41.78Average Eta RSE % 19.41 19.47 19.44 Additive Error 0.887 (9.26) 0.887(9.30) 0.887 (9.28) Objective Function 2641.12  2640.27  2639.39 Objective Function - Baseline −0.85 −1.73 Number of Evaluations (TimeTaken)    197 (0:0:26)    238 (0:0:22)    229 (0:0:23) Number ofSignificant Figures 4.2 5.6 4.9 Maximum Eigenvalue ratio  3.608  4.030 7.290 ^(a)EC₅₀ = θ1 × (Scaled Dose){circumflex over ( )} θ2, where“scaled dose” = 1 for no fentanyl, 2 for 50 μg and 3 for 75 μg.

TABLE 5 Parameter Value Systemic Clearance 62.4 L/h Inter-TissueClearance 65.4 L/h Central Volume of Distribution 11.9 L PeripheralVolume of Distribution 513 L

TABLE 6 Summary file CNS7056FEN01AS CNS7056FEN03S CNS7056FEN04SCNS7056FEN05S CNS7056FEN06S Number of Individuals/Records 99/276499/2764 99/2764 99/2764 99/2764 Summary of THETAs and RSE % EC₅₀ (μg/ml)0.349 (4.38) 0.348 (—) 0.342 (4.44) 0.346 (4.30) 0.348 (4.39) HillCoefficient (γ)  3.9 (6.87) 3.88 (—)  4.08 (7.15)  4.24 (7.52)  4.4(5.97) E_(MIN)  0.0 (—) 0.0 (—)  0.0 (—)  0.0 (—)  0.0 (—) E_(MAX)  5.0(—) 5.0 (—)  5.0 (—)  5.0 (—)  5.0 (—) ke0 (h⁻¹)  14.8 (5.08) 15 (—) 15.1 (4.78)  14.4 (4.57)  13.9 (4.70) Conc.-EQ. −4.46 (—) 0.00 (—)  21.5 (16.6)  23.7 (30.7) Effect of Scope on EC₅₀ 0.116 (5.95) 0.145(5.27) 0.144 (4.92) Average THETA RSE % 5.45 — 5.59 7.66 10.14 Summaryof ETAs and RSE % EC₅₀ (%) 36.33 (16.0) 36.48 (—) 36.48 (16.0) 35.54(15.8) 35.54 (16.0) Hill Coefficient (γ) (%) 55.55 (24.3) 55.43 (—)58.80 (25.1) 60.39 (25.4) 61.52 (25.5) ke0 (%) 35.07 (18.2) 35.07 (—)32.36 (16.7) 31.39 (16.5) 32.12 (16.8) Conc.-EQ. 162.2 (82.6) AverageETA 42.32  42.33  42.55  42.45  72.86 Average ETA RSE % 19.54  — 19.32 19.26  35.29 Additive Error (±) 0.886 (9.26) 0.886 (—) 0.872 (9.20)0.869 (9.30) 0.854 (9.50) Objective Function 2637.82   2637.10  2570.26   2554.00   2518.82  Objective Function - Baseline −0.72 −67.57  −83.82  −119.00  Number of Evaluations    189 (0:0:36) 245(0:0:51)    337 (0:1:12)    350 (0:1:17)    254 (0:1:11) (Time Taken)Number of Significant Figures 4.50 7.60 6.50 5.30  6.00 Error MessagesNone 134 (Rounding Error) None None None Maximum Eigenvalue ratio 3.591.00 3.62 4.47  4.67

TABLE 7 Summary file CNS7056FEN01AS CNS7056FEN07S CNS7056FEN08SCNS7056FEN09S CNS7056FEN12S CNS7056FEN13S Number of Individuals/Records99/2764 99/2764 99/2764 99/2764 99/2764 99/2764 Length of Stimuli 1 min½ min ½ min ½ min ½ min Summary of THETAs and RSE % EC₅₀ (μg/ml) 0.349(4.38) 0.336 (4.28) 0.328 (4.48) 0.331 (4.16) 0.323 (4.42) 0.321 (4.33)Hill Coefficient (γ) 3.9 (6.87) 4 (2.6) 3.96 (6.18) 4.43 (6.41) 4.11(6.54) 4.18 (7.03) E_(MIN) 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—) 0.0(—) E_(MAX) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) ke0 (h⁻¹)14.8 (5.08) 14.2 (4.66) 13.7 (4.30) 12.8 (4.02) 14.1 (4.19) 13.9 (4.51)Effect of Stimulus 1.24 (1.11) 1.27 (0.85) 1.23 (0.89) 1.25 (0.82) 1.29(2.43) on EC₅₀ Conc.-EQ. 41.3 (7.21) Effect of Scope on 0.155 (4.74)0.115 (5.41) 0.105 (6.2) EC₅₀ Average THETA 5.45 3.17 3.96 4.58 4.284.90 RSE % Summary of ETAs and RSE % EC₅₀(%) 36.17 (16.0) 35.86 (15.7)35.70 (15.8) 34.42 (15.9) 36.17 (16.3) 35.07 (16.1) Hill Coefficient (γ)55.67 (24.3) 51.09 (22.1) 47.95 (20.9) 52.20 (22.7) 49.35 (21.9) 54.25(23.7) (%) ke0 (%) 35.07 (18.2) 32.43 (16.8) 31.51 (16.1) 28.25 (15.0)29.25 (15.2) 30.47 (15.9) Effect of Stimulus 10.70 (8.05) on EC₅₀Average ETA 42.31 39.80 38.39 38.29 38.26 32.63 Average ETA 19.55 18.2417.63 17.92 17.86 15.94 RSE % Additive Error (±) 0.886 (9.26) 0.849(9.28) 0.832 (9.38) 0.814 (9.11) 0.822 (9.26) 0.808 (9.14) ObjectiveFunction 2637.23 2400.01 2285.97 2189.77 2231.79 2200.91 ObjectiveFunction - −237.22 −351.26 −447.46 −405.44 −436.32 Baseline Number of191 (0:0:38) 241 (0:1:4) 214 (0:0:53) 273 (0:0:58) 211 (0:0:48) 263(0:1:9) Evaluations (Time Taken) Number of 4.80 7.50 7.40 7.30 6.60 6.40Significant Figures Maximum 3.58 3.64 3.76 4.68 3.71 5.52 Eigenvalueratio

TABLE 8 Summary file MOAASALL01S MOAASALL18S MOAASALL21S MOAASALL22SMOAASALL23S MOAASALL33S Number of Individuals/Records 99/2764 99/276499/2764 99/2764 99/2764 99/2764 Length of Additional Stimuli 1 min 1 min½ min Summary of Thetas and RSE % EC₅₀ (μg/ml) 0.349 (4.35) 0.342 (4.38)0.336 (4.34) 0.336 (4.31) 0.329 (4.34) 0.342 (4.41) Hill Coefficient (γ)3.92 (6.76) 4.1 (7.04) 4.02 (6.54) 3.98 (6.50) 3.92 (6.09) 4.21 (7.22)E_(MIN) 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—) E_(MAX) 5.0 (—)5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) ke0 (h⁻¹) 14.8 (5.08) 15.1(4.77) 14.2 (4.65) 14.4 (4.86) 14 (4.63) 15 (4.64) Effect of Scope on0.116 (5.95) 0.098 (19.8) EC₅₀ Effect of Stimulus 1.25 (1.17) 0.574(1.21)^(a) 0.589 (1.03)^(a) on EC₅₀ Average Theta 5.40 5.54 4.18 4.234.03 9.02 RSE % Summary of Etas and RSE % EC₅₀ (%) 36.02 (15.9) 36.17(15.9) 35.54 (16.0) 35.86 (16.2) 35.86 (16.4) 36.48 (16.0) HillCoefficient (γ) 54.49 (23.9) 57.77 (24.8) 50.35 (22.3) 51.71 (22.7)48.59 (21.4) 59.37 (25.3) (%) ke0 (%) 35.23 (18.3) 32.43 (16.8) 32.43(17.0) 33.27 (16.9) 31.98 (16.2) 31.53 (16.4) Effect of Scope on 114.7(68.5) EC₅₀ (%) Average Eta (%) 41.91 42.13 39.44 40.28 38.81 60.53Average Eta 19.41 19.20 18.50 18.63 18.06 31.59 RSE % Additive Error (±)0.887 (9.26) 0.874 (9.20) 0.847 (9.29) 0.845 (9.31) 0.830 (9.29) 0.857(9.31) Objective Function 2641.12 2573.85 2387.30 2379.23 2269.702530.09 Objective Function - −67.27 −253.82 −261.90 −371.43 −111.03Baseline Number of 197 (0:0:26) 247 (0:0:29) 248 (0:0:27) 259 (0:0:29)249 (0:0:29) 316 (0:0:46) Evaluations (Time Taken) Number of 4.20 4.504.20 5.00 4.40 4.60 Significant Figures Maximum 3.61 3.62 4.78 3.98 3.423.72 Eigenvalue ratio ^(a)Size of spike taken into account

TABLE 9 Summary file MOAASALL25S MOAASALL26S MOAASALL27S MOAASALL29SMOAASALL31S MOAASALL32S Number of Individuals/Record 99/2764 99/276499/2764 99/2764 99/2764 99/2764 Length of Additional Stimuli (mins.) 1min ½ min ½ min ½ min ½ min ½ min Summary of Thetas and RSE % EC₅₀(μg/ml) 0.332 (4.30) 0.325 (4.36) 0.322 (4.28) 0.323 (4.45) 0.323 (4.42)0.323 (4.48) Hill Coefficient (γ) 4.12 (6.79) 4.04 (6.31) 4.2 (6.88)4.05 (6.41) 4.14 (6.30) 4.29 (6.57) E_(MIN) 0.0 (—) 0.0 (—) 0.0 (—) 0.0(—) 0.0 (—) 0.0 (—) E_(MAX) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—) 5.0(—) ke0 (h⁻¹) 14.7 (4.54) 14.2 (4.48) 13.9 (4.55) 14.2 (4.59) 14.1(4.22) 14.1 (4.13) Effect of Scope on 0.103 (6.08) 0.088 (7.09) 0.102(6.38) 0.098 (6.84) 0.109 (5.72) 0.089 (24.5) EC₅₀ Effect of Stimulus0.564 (1.08) ^(a) 0.58 (0.95) ^(a) 1.29 (2.34) 0.589 (2.34) ^(a) 1.25(0.84) 1.24 (0.79) on EC₅₀ Average Theta 4.56 4.64 4.89 4.93 4.30 8.11RSE % Summary of Etas and RSE % EC₅₀ 36.02 (16.1) 36.02 (16.4) 34.74(15.9) 35.38 (16.4) 35.86 (16.2) 36.17 (16.3) Hill Coefficient (γ) 53.41(23.6) 48.34 (22.6) 52.93 (23.4) 48.59 (22.0) 48.34 (21.6) 51.46 (23.1)ke0 30.20 (15.2) 30.09 (15.5) 30.58 (15.9) 30.70 (16.2) 29.47 (15.2)28.76 (14.5) Effect of Stimulus 10.27 (7.87) 10.12 (7.54) on EC₅₀ Effectof Scope on 163.3 (100) EC₅₀ Average Eta 39.88 38.15 32.13 31.20 37.8969.95 Average Eta RSE % 18.34 18.20 15.80 15.57 17.70 38.70 AdditiveError (±) 0.838 (9.34) 0.825 (9.33) 0.807 (9.23) 0.816 (9.36) 0.821(9.30) 0.798 (9.40) Objective Function 2342.71 2244.30 2193.54 2228.472221.61 2152.84 Objective Function - −231.14^(b) −329.55^(b) −380.30^(b)−345.38^(b) −352.23^(b) −421.01^(b) Baseline Number of Evaluations 232(0:0:26) 306 (0:0:35) 344 (0:0:46) 283 (0:0:38) 321 (0:0:32) 489 (0:1:7)(Time Taken) Number of Significant 4.50 4.20 4.00 4.10 4.70 5.50 FiguresMaximum Eigenvalue 4.59 4.08 5.62 5.10 3.76 4.13 ratio ^(a)Size of spiketaken into account ^(b)Relative to MOAASALL18S (Table 8)

TABLE 10 Summary file CNS7056FEN09S CNS7056FEN10S CNS7056FEN11SCNS7056FEN14S CNS7056FEN18S CNS7056FEN19S Number of Individuals/Records99/2764 99/2764 99/2764 99/2764 99/2764 99/2764 Summary of THETAs andRSE % EC₅₀ 0.331 (4.16) 0.333 (4.50) 0.328 (4.26) 0.331 (2.35) 0.331(4.44) 0.333 (4.71) (μg/ml) Hill Coefficient (γ) 4.43 (6.41) 4.6 (7.32)4.41 (7.30) 4.64 (2.15) 4.56 (7.12) 4.69 (6.09) E_(MIN) 0.0 (—) 0.0 (—)0.0 (—) 0.0 (—) 0.0 (—) 0.0 (—) E_(MAX) 5.0 (—) 5.0 (—) 5.0 (—) 5.0 (—)5.0 (—) 5.0 (—) ke0 (h⁻¹) 12.8 (4.02) 12.5 (5.00) 12.9 (4.20) 12.4(1.52) 12.9 (3.89) 12.6 (4.36) Effect of Stimulus 1.23 (0.89) 1.22(0.72) 1.26 (2.12) 1.25 (0.88) 1.22 (0.81) 1.21 (0.68) on EC₅₀ Conc.-EQ.41.3 (7.21) 33.1 (29.2) 33.2 (8.37) 30.3 (28.8) 38.3 (7.72) 28.2 (30.6)Effect of Scope on 0.155 (4.74) 0.158 (4.22) 0.147 (4.97) 0.143 (4.10)0.131 (17.2) 0.133 (13.9) EC₅₀ Average THETA 4.58 8.50 5.21 6.64 6.8810.09 RSE % Summary of ETAs and RSE % EC₅₀ (%) 34.42 (15.9) 34.74 (16.0)33.77 (15.7) 33.93 (6.97) 34.91 (15.3) 35.23 (14.1) Hill Coefficient (γ)52.20 (22.7) 55.20 (24.6) 54.61 (24.3) 57.88 (15.0) 56.49 (23.3) 59.03(25.8) (%) ke0 (%) 28.25 (15.0) 32.93 (16.2) 28.95 (15.8) 32.76 (8.85)29.13 (15.0) 34.09 (15.5) Conc.-EQ. 184.1 (91.1) 200.0 (78.2) 214.1(113) Effect of Stimulus 9.277 (7.17) 8.659 (4.36) on EC₅₀ Effect ofScope on 99.28 (60.9) 90.57 (56.4) EC₅₀ Average ETA 38.29 76.77 31.6566.66 54.96 86.61 Average ETA 17.92 37.04 15.78 22.71 28.69 45.05 RSE %Additive Error (±) 0.814 (9.11) 0.790 (9.44) 0.803 (9.21) 0.778 (9.81)0.790 (9.51) 0.767 (9.42) Objective Function 2189.77 2126.25 2168.992102.48 2116.61 2053.72 Objective Function - −63.52 −20.79 −87.29 −73.17−136.05 Baseline Number of 273 (0:0:58) 432 (0:1:40) 333 (0:1:12) 390(0:1:47) 298 (0:1:11) 378 (0:1:40) Evaluations (Time Taken) Number of7.30 6.10 6.20 8.20 7.50 10.10 Significant Figures Maximum 4.68 5.387.17 13.35 5.69 6.43 Eigenvalue ratio

TABLE 11 Adjusted Score Parameters Total Scores Predicted/Observed Run“0” “5” E_(MIN) ^(e) E_(MAX) ^(e) 0 1 2 3 4 5 Mean CV % Etas OFV FEN10S  0.01 5.0   0 5 208 364 291 354 420 1127 1.20 59.82 4^(c) 2126.25FEN16S −1.5 5.1 −1.96 4.97 462 187 232 278 437 1168 1.02 16.30 4^(c)3616.30 FEN17S −1.5 5.0 −1.83 4.98 468 173 232 270 462 1159 1.01 13.304^(c) 3552.02 FEN19S   0.01 5.0   0 5 230 342 286 347 416 1143 1.1855.16 5^(cd) 2053.72 FEN20S −1.25 5.05 −1.65 4.95 433 211 232 298 4471143 1.05 21.02 4^(c) 3364.80 FEN21S −1.3 5.05 −1.55 4.90 452 181 225291 429 1186 1.02 14.52 5^(cd) 3293.07 FEN22S −1.3 5.05 −1.72 4.95 434211 230 298 446 1145 1.05 21.10 4^(d) 3410.00 FEN23S −1.25 5.0 −1.484.85 450 184 219 295 445 1171 1.02 14.82 5^(cd) 3216.41 FEN24S −1.25 5.0−1.51 4.85 434 202 234 280 454 1160 1.04 19.44 4^(d) 3289.08 FEN25S−1.25 5.0 −1.67 4.88 436 207 227 301 461 1132 1.05 19.77 4^(c) 3337.03FEN26S −1.3 5.0 −1.54 4.84 454 180 219 295 444 1172 1.02 13.88 5^(cd)3259.55 FEN27S −1.25 5.0 −1.62 4.91 430 210 240 305 479 1100 1.06 19.854^(b) 3415.58 FEN28S −1.25 5.0 −1.45 4.87 436 201 236 304 445 1142 1.0518.09 4^(a) 3408.37 FEN29S −1.25 5.0 −1.58 4.89 434 211 238 300 457 11241.06 20.56 3 3423.35 FEN30S   0.01 5.0 −0.105 4.94 233 330 297 346 4401118 1.18 52.15 4^(d) 2109.72 FEN32S −1.3 5.0 −1.67 4.90 436 204 240 303478 1103 1.06 18.32 4^(b) 3461.03 Observed — — — — 435 141 237 330 4771144 — — ^(a)IIV on additional stimulus ^(b)IIV on E_(MIN) ^(c)IIV onequivalence factor ^(d)IIV on scoping factor ^(e)Integer values ofE_(MAX) and E_(MIN) are fixed; all other values are fitted by the model

TABLE 12 Summary file MOAASALLMIN62SC MOAASALLMIN65SC CNS7056FEN31SCNS7056FEN32S CNS7056FEN26S Number of Individuals/Records 99/276499/2764 99/2764 99/2764 99/2764 Summary of Thetas and RSE % EC₅₀ (μg/ml)0.367 (5.01) 0.369 (5.01) 0.378 (1.51) 0.375 (1.63) 0.380 (0.94) Hillcoefficient (γ)  4.20 (7.47)  4.62 (8.41)  5.04 (4.12)  4.30 (2.06) 5.16 (2.32) E_(MIN) −1.56 (13.0) −1.54 (7.20) −1.57 (2.99) −1.67 (3.11)−1.54 (1.75) E_(MAX)  4.88 (1.20)  4.85 (0.87)  4.84 (0.15)  4.90 (0.31) 4.84 (0.15) ke0 (h⁻¹)  13.2 (3.83)  13.2 (4.01)  12.2 (1.01)  12.4(1.38)  12.1 (0.91) Effect of Additional Stimulus on EC₅₀  1.28 (1.08) 1.25 (0.93)  1.23 (0.54)  1.26 (0.92)  1.22 (0.46) Fentanylconcentration-equivalence  40.1 (6.28)  32.0 (8.87)  28.0 (24.8) Effectof Scope on EC₅₀ 0.089 (5.75) 0.058 (35.2) 0.098 (6.04)  0.13 (5.34)0.101 (4.78) Average Theta RSE %  5.35 8.82  2.83  2.96  4.52 Summary ofEtas and RSE % EC₅₀ 34.91 (15.8) 35.23 (14.8) 32.93 (7.68) 33.10 (9.51)33.43 (6.80) Hill coefficient 53.17 (23.0) 69.49 (30.2) 75.07 (23.0)54.25 (11.9) 77.04 (20.4) E_(MIN) 29.73 (15.2) 28.87 (11.7) 31.91 (8.04)29.06 (11.6) 34.09 (7.12) Effect of Scope on EC₅₀ 327.1 (186)  170.1(58.6) 134.2 (45.0) Fentanyl concentration-equivalence 192.6 (59.3)E_(MIN) 94.18 (38.7) 93.78 (38.1) Average Eta 53.00 115.20  77.53 52.5594.29 Average Eta RSE % 23.24 60.86  24.38 17.82 27.76 Additive Error(±) 1.019 (10.3) 0.993 (10.0) 0.978 (8.69) 1.014 (9.35) 0.952 (9.17)Objective Function 3480.36  3383.98   3332.57  3461.03  3259.55 Objective Function - Baseline — — −51.41  −19.32  −73.02  Number ofEvaluations    277 (0:0:52)    312 (0:0:56)    348 (0:2:14)    439(0:1:46)    454 (0:2:12) (Time Taken) Number of Significant Figures 7.50 7.20  8.20  8.40  8.40 Maximum Eigenvalue ratio 10.11 9.46 91.5590.28 18.13

TABLE 13 Summary file CNS7056FEN19S^(a) CNS7056FEN135S19^(b)CNS7056FEN159S19^(c) Number of Individuals/Records 99/2764 99/276499/2764 Summary of Thetas and RSE % EC₅₀ (μg/ml) 0.333 (4.71) 0.339(1.36) 0.333 (0.84) Hill coefficient (γ) 4.69 (6.09) 4.74 (2.06) 4.7(2.34) E_(MIN) 0.0 (—) 0.0 (—) 0.0 (—) E_(MAX) 5.0 (—) 5.0 (—) 5.0 (—)ke0 (h⁻¹) 12.6 (4.36) 12.8 (1.01) 12.6 (1.14) Effect of Stimulus on EC₅₀1.21 (0.68) 1.2 (0.40) 1.21 (0.61) Fentanyl concentration-equivalence28.2 (30.6) 30.9 (20.4) 28.9 (22.5) Effect of Scope on EC₅₀ 0.133 (13.9)0.13 (3.56) 0.135 (5.21) Average THETA RSE % 10.09 4.81 5.45 Summary ofEtas and RSE % EC₅₀ (%) 35.23 (14.1) 35.23 (5.81) 35.86 (5.67) Hillcoefficient (%) 59.03 (25.8) 59.49 (13.1) 59.26 (11.9) E_(MIN) (%) 34.09(15.5) 33.43 (6.71) 35.70 (7.08) Effect of Scope on EC₅₀ (%) 90.57(56.4) 85.42 (27.9) 84.31 (23.9) Fentanyl concentration-equivalence214.1 (113.) 181.8 (64.9) 212.8 (78.0) Average ETA 86.61 79.08 85.59Average ETA RSE % 45.05 23.71 25.35 Additive Error (±) 0.767 (9.42)0.768 (9.11) 0.766 (9.53) Objective Function 2053.72 2052.64 2048.04Objective Function - Baseline — −1.08 −5.68 Number of Evaluations (TimeTaken) 378 (0:1:40) 360 (0:1:52) 384 (0:1:40) Number of SignificantFigures 10.10 8.20 8.70 Maximum Eigenvalue ratio 6.43 12.99 11.81Summary file CNS7056FEN26S^(a) CNS7056FEN135S26^(b) CNS7056FEN159S26^(c)Number of Individuals/Records 99/2764 99/2764 99/2764 Summary of Thetasand RSE % EC₅₀ (μg/ml) 0.380 (0.94) 0.386 (2.58) 0.381 (4.17) Hillcoefficient (γ) 5.16 (2.32) 5.23 (0.54) 5.19 (0.49) E_(MIN) −1.54 (1.75)−1.49 (1.67) −1.52 (1.76) E_(MAX) 4.84 (0.15) 4.84 (0.17) 4.84 (0.13)ke0 (h⁻¹) 12.1 (0.91) 12.3 (1.19) 12.1 (0.69) Effect of Stimulus on EC₅₀1.22 (0.46) 1.21 (0.46) 1.22 (0.63) Fentanyl concentration-equivalence28.0 (24.8) 30.6 (17.9) 28.9 (19.9) Effect of Scope on EC₅₀ 0.101 (4.78)0.096 (4.23) 0.104 (19.1) Average THETA RSE % 4.52 3.60 5.87 Summary ofEtas and RSE % EC₅₀ (%) 33.43 (6.80) 33.77 (6.08) 33.77 (5.29) Hillcoefficient (%) 77.04 (20.4) 77.14 (21.0) 77.45 (21.0) E_(MIN) (%) 34.09(7.12) 33.10 (6.63) 36.02 (6.03) Effect of Scope on EC₅₀ (%) 134.2(45.0) 117.3 (33.6) 120.4 (39.7) Fentanyl concentration-equivalence192.6 (59.3) 162.2 (52.3) 195.1 (62.3) Average ETA 94.29 84.73 92.55Average ETA RSE % 27.76 23.93 26.89 Additive Error (±) 0.952 (9.17)0.954 (9.37) 0.950 (9.38) Objective Function 3259.55 3262.71 3255.65Objective Function - Baseline — 3.17 −3.90 Number of Evaluations (TimeTaken) 454 (0:2:12) 533 (0:2:50) 489 (0:2:8) Number of SignificantFigures 8.40 8.50 8.30 Maximum Eigenvalue ratio 18.13 13.77 14.10^(a)Three-compartment model, ^(b)Four-compartment model,^(c)Three-compartment model with heart-rate predicting cardiac outputand central volume

TABLE 14 Concentration - EC₅₀ ke0 equivalence Scoping (μg/ml) Gamma(h⁻¹) factor Factor N 99 99 99 99 36 Mean 0.385 6.435 12.35 40.78 0.178SD 0.104 3.946 3.01 45.27 0.145 SE 0.011 0.399 0.30 4.57 0.015 Minimum0.202 1.151 5.58 5.94 0.023 Median 0.380 5.229 12.14 27.99 0.110 Maximum0.736 21.31 23.30 330.8 0.587 CV % 27.0 61.3 24.4 111.0 81.3 GeometricMean 0.372 5.480 11.98 31.65 0.129 Mean of the Logs −0.989 1.701 2.483SD of the Logs 0.263 0.576 0.252

TABLE 15 Scoped Zero after Average MOAA/S Loading Total Regimen^(a)Dropouts Scores Failures Dose Average Dose (mg) (%) (%) (%) (%) Top-ups(mg)  9/4.5^(a) 10 12.54 2 897 3.133 23.10 9/4   13 10.08 10 897 3.34422.38 9/3.5 19 7.76 27 897 3.579 21.53 9/3   27 6.18 53 897 3.869 20.619/2.5 45 5.25 99 897 4.192 19.48 8/4.5 15 10.87 2 830 3.275 27.74 8/4  20 8.20 13 830 3.478 21.91 8/3.5 26 5.89 29 830 3.752 21.13 8/3   494.24 50 830 3.999 20.00 8/2.5 67 3.30 107 830 4.291 18.73 7/4.5 19 9.964 719 3.428 22.43 7/4   25 7.20 12 719 3.655 21.62 7/3.5 46 4.69 24 7193.876 20.57 7/3   69 2.91 48 719 4.119 19.36 7/2.5 96 1.88 114 719 4.40018.00 7/2   151 1.42 197 719 4.556 16.11 6/4.5 24 9.48 4 566 3.591 22.166/4   45 6.54 14 566 3.790 21.16 6/3.5 65 3.84 25 566 4.000 20.00 6/3  97 2.07 50 566 4.230 18.68 6/2.5 157 1.08 106 566 4.377 16.94 5/4.5 449.57 3 380 3.668 21.51 5/4   68 6.44 8 380 3.859 20.44 5/3.5 97 3.78 17380 4.079 19.28 5/3   153 1.83 43 380 4.218 17.65 5/2.5 237 0.72 68 3804.234 15.59

TABLE 16 Geom. Mean Mean S.D. Sub- (Typical of of ject Parameter UnitsValue) Logs. Logs 1210 Clearance (l/h) 49.16 3.895 0.138 43.92 V1 (l) 1.770 0.571 0.979 6.107 V2 (l)  1.103 0.098 0.110 1.209 V3 (l)  0.717−0.333 0.110 0.786 Q4 (l/h) 74.56 74.56 Q5 (l/h) 25.74 25.74 V4 (l)13.68 2.616 0.420 21.59 V5 (l) 23.24 3.146 0.186 24.18 Q (Q2, Q3) (l/h)173.4  173.4 Q1 = (Q − Q4 − Q5) (l/h) 73.06 73.06 EC₅₀ (μg/ml)  0.363−1.023 0.274 0.180 Hill coefficient  4.03 1.419 0.357 6.627 ke0 (h⁻¹)13.3  2.584 0.210 12.17 E_(MIN)   −1.50 a −0.742 E_(MAX) 5.0 5.0 Effectof Pain on EC₅₀  1.28 1.28 Effect of Scope on  0.095 0.095 EC₅₀ Weight(kg) 77.20 4.346 0.110 84.6 a: As E_(MIN) was negative, the naturallogarithms could not be calculated and its was set to the populationmean (−1.50) for all subjects. The compartmental volumes and clearancesare numbered as follows: (1) = central, (2) = pulmonary, (3) = arterial,(4) = peripheral, (5) = deep. V2 (weight/70) and V3 (0.65 × weight/70)are calculated from body-weights.

TABLE 17 Minimum Dropouts Zero MOAA/S Failures Average Regimen DosingGap (‰) Scores (%) (‰) Top-ups 6/4 2 min 45 6.54 14 3.790 6/4 3 min 456.50 2 3.789 6/4 4 min 45 6.43 0 3.775 6/3 2 min 97 2.07 50 4.230 6/3 3min 97 2.05 34 4.221 6/3 4 min 97 1.97 2 4.199 6/3 5 min 97 1.81 303.891 6/3 6 min 97 1.72 40 3.760

TABLE 18 Scoped after CNS 7056 CNS 7056- Zero Loading AverageRegimen^(a) Fentanyl Fentanyl Dropouts MOAA/S Failures Dose no. of (mg)Dose (μg) Gap (min) (%) Scores (%) (%) (%) Top-ups  6/4^(a) 50 4 min 429.95 86 604 3.955 6/4 75 4 min 28 10.6 87 689 3.899 6/4 100 4 min 2411.8 83 754 3.806 5/3 0 4 min 242 3.17 116 211 4.205 5/3 50 4 min 1333.88 168 437 4.412 5/3 75 4 min 102 4.53 175 529 4.423 5/3 100 4 min 795.39 174 637 4.394 6/3 0 4 min 168 3.42 148 374 4.337 6/3 50 4 min 934.51 197 604 4.387 6/3 75 4 min 75 5.39 194 689 4.335 6/3 100 4 min 576.60 194 754 4.292 7/3 0 4 min 119 4.00 161 545 4.338 7/3 50 4 min 645.51 170 735 4.31  7/3 75 4 min 47 6.83 166 791 4.259 7/3 100 4 min 338.30 166 839 4.211 8/3 0 4 min 80 4.91 159 694 4.295 8/3 50 4 min 427.08 156 829 4.208 8/3 75 4 min 27 8.47 162 868 4.151 8/3 100 4 min 2410.3 143 897 4.072 9/3 0 4 min 52 6.20 153 793 4.219 9/3 50 4 min 269.02 147 882 4.087 9/3 75 4 min 20 10.8 138 913 4.017 9/3 100 4 min 1812.6 130 925 3.925 ^(a)Loading dose/Top-up doses

TABLE 19 Geom. Mean Mean S.D. Sub- (Typical of of ject Parameter UnitsValue) Logs. Logs. 1210 Clearance (l/h) 49.16 3.895 0.138 43.92 V1 (l) 1.770 0.571 0.979 6.107 V2 (l)  1.103 0.098 0.110 1.209 V3 (l)  0.717−0.333 0.110 0.786 Q4 (l/h) 74.56 74.56 Q5 (l/h) 25.74 25.74 V4 (l)13.68 2.616 0.420 21.59 V5 (l) 23.24 3.146 0.186 24.18 Q (Q2, Q3) (l/h)173.4  173.4 Q1 = (Q − Q4 − Q5) (l/h) 73.06 73.06 EC₅₀ (μg/ml)  0.380−0.989 0.263 0.269 Hill coefficient  5.16 1.701 0.576 6.596 ke0 (h⁻¹)12.1  2.483 0.252 6.18 E_(MIN) −1.54 −1.54 E_(MAX)  4.84 4.84 Effect ofPain on EC₅₀  1.216 1.216 Effect of Scope on     0.129 ^(a) −2.05 0.8370.230 EC₅₀ Fentanyl-equivalence 28.0  3.455 0.604 126.8 factor Weight(kg) 77.20 4.346 0.110 84.6 ^(a) Geometric mean of the 36 subjects fromStudy CNS 7056-002 who completed the study. The compartmental volumesand clearances are numbered as follows: (1) = central, (2) = pulmonary,(3) = arterial, (4) = peripheral, (5) = deep. V2 (weight/70) and V3(0.65 × weight/70) are calculated from body-weights.

TABLE 20 CNS 7056 CNS 7056- Zero Scoped after Average Regimen^(a)Fentanyl Fentanyl Dropouts MOAA/S Failures Loading Dose no. of (mg) Dose(μg) Gap (min) (%) Scores (%) (%) (%) Top-ups  6/3^(a) 50 0.00 89 4.75156 586 4.262 6/3 50 1.00 86 4.79 168 575 4.343 6/3 50 1.50 88 4.98 168603 4.348 6/3 50 2.00 89 5.04 169 617 4.371 6/3 50 2.25 86 4.79 171 5984.367 6/3 50 2.50 91 4.69 162 621 4.316 6/3 50 3.00 95 4.68 167 6244.324 6/3 50 3.50 91 4.70 187 600 4.372 6/3 50 4.00 93 4.51 197 6044.387 6/3 50 4.25 98 4.54 205 618 4.343 6/3 50 4.50 96 4.71 218 6114.391 6/3 50 5.00 99 4.66 216 613 4.406 6/3 50 6.00 106 4.33 155 6084.347 6/3 50 9.00 116 4.02 159 569 4.358 ^(a)Loading dose/Top-up doses

TABLE 21 Scoped after CNS 7056 CNS 7056- Zero Loading AverageRegimen^(a) Fentanyl Fentanyl Dropouts MOAA/S Failures Dose no. of (mg)Dose (μg) Gap (min)^(b) (%) Scores (%) (%) (%) Top-ups  8/3^(a) 100 0.2024 11.275 123 873 3.912 7/2 100 0.20 76 6.2375 301 800 4.649 5/3 1000.20 77 6.2075 158 556 4.221 ^(a)Loading dose/Top-up doses ^(b)CNS 7056infusion started immediately after fentanyl infusion completed (~12seconds)

TABLE 22 Success rate n/N (%) (ITT) Remimazolam - 8.0/3.0 mg 37/40(92.5%), p = 0.066 Remimazolam - 7.0/2.0 mg 38/40 (95.0%), p = 0.025Remimazolam - 5.0/3.0 mg 39/40 (97.5%), p = 0.007 Midazolam - 2.5/1.0 mg30/40 (75.0%), p = 0.007 Descriptive p values for remimazolam representpair-wise comparisons between each group and midazolam Descriptive pvalue for midazolam represents comparison to remimazolam groups combined

TABLE 23 Drug/dose Clinical Phase tested Success rate n/N (%)Remimazolam - 8.0/3.0 mg 37/40 (92.5%) Remimazolam - 7.0/2.0 mg 38/40(95.0%) Remimazolam - 5.0/3.0 mg 39/40 (97.5%) Phase IIb (StudyCNS7056-004) Midazolam 2.5/1.0 mg 30/40 (75.0%) Phase IIb (StudyCNS7056-004) Remimazolam (combined success rate 24/29 (82.8%) of 2highest doses) Phase Ib (Study CNS7056-002) Fospropofol 6.5 mg/kg(labelled dose)* Phase II: 18/26 (69.2%) Phase II and Phase III PhaseIII: 137/158 (86.7%) Midazolam 0.02 mg/kg* Phase II: 21/26 (80.8%) PhaseII and Phase III Phase III: 36/52 (69.2%) *Success rates taken fromfospropofol NDA Midazolam dose for procedural sedation is 1-2.5 mginitially, with titration doses of 1 mg—equivalent to 0.014—0.036 mg/kginitially, for a 70 kg person

TABLE 24 Time to ITT Population Procedure Procedure No. of Start*Duration Top-up All data are means (SD) (minutes) (minutes) DosesRemimazolam - 8.0/3.0 mg 2.23 (1.44) 13.80 (6.15) 1.43 (1.52)Remimazolam - 7.0/2.0 mg 3.03 (2.17) 14.33 (5.46) 2.35 (1.97)Remimazolam - 5.0/3.0 mg 2.65 (1.42) 12.90 (4.92) 1.98 (1.64)Midazolam - 2.5/1.0 mg 4.80 (3.19) 13.32 (7.01) 2.48 (1.77) *afterinitial dose

TABLE 25 Time to fully alert (mins)* Mean (SD) MOAA/S ITT populationRemimazolam - 8.0/3.0 mg 13.6 (7.48) Remimazolam - 7.0/2.0 mg 11.3(5.69) Remimazolam - 5.0/3.0 mg 13.3 (7.21) Midazolam - 2.5/1.0 mg 15.2(7.43) *first of three consecutive MOAA/S scores of 5 after the lastinjection of study drug

TABLE 26 Time to ready for discharge (mins)* Mean (SD) After lastinjection ITT population Remimazolam - 8.0/3.0 mg 16.8 (7.54)Remimazolam - 7.0/2.0 mg 14.0 (6.28) Remimazolam - 5.0/3.0 mg 13.5(4.83) Midazolam - 2.5/1.0 mg 17.1 (7.33) first of three consecutiveAldrete scores of ≧9

We claim:
 1. A method of sedating a subject, comprising administering tothe subject an initial dose of the besylate salt of3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-][1,4]benzodiazepin-4-yl]-propionicmethyl ester of formula (I)

wherein the initial dose is a fixed dose of between about 2 mg and about10 mg and is irrespective of the body weight of the subject.
 2. Themethod of claim 1, wherein the initial fixed dose of the besylate saltof the compound of formula (I) is selected from the group consisting ofbetween about 3 mg and about 10 mg; between about 3 mg and about 9 mg;and between about 5 mg and about 8 mg.
 3. The method of claim 1, furthercomprising administering to the subject one or more subsequent doses ofthe besylate salt of the compound of formula (I), wherein the one ormore subsequent doses are fixed doses, are irrespective of body weight,and are selected from the group consisting of between about 1 and about4 mg; between about 1.5 mg and about 3.5 mg; and between about 2 andabout 3 mg.
 4. The method of claim 3, wherein the initial fixed dose andthe one or more subsequent fixed doses of the besylate salt of thecompound of formula (I) administered to the subject are selected fromthe group consisting of: a) about 8 mg of an initial fixed dose andabout 3 mg of a subsequent fixed dose, b) about 7 mg of an initial fixeddose and about 2 mg of a subsequent fixed dose, and c) about 5 mg of aninitial fixed dose and about 3 mg of a subsequent fixed dose.
 5. Themethod of claim 3, wherein the one or more subsequent fixed doses of thebesylate salt of the compound of formula (I) is administered to thesubject not earlier than 2 minutes from the time the initial fixed doseis administered to the subject.
 6. The method of claim 3, wherein notmore than six subsequent fixed doses of the besylate salt of thecompound of formula (I) are administered to the subject.
 7. The methodof claim 1, wherein the besylate salt of the compound of formula (I) isadministered to the subject intravenously.
 8. A method of sedating asubject, comprising administering to the subject a dose of the besylatesalt of3-[(4S)-8-bromo-1-methyl-6-(2-pyridinyl)-4H-imidazo[1,2-a][1,4]benzodiazepin-4-yl]-propionicmethyl ester of formula (I),

wherein the dose is a fixed dose of between about 2 mg and about 10 mgand is irrespective of the body weight of the subject.
 9. The method ofclaim 8, wherein the dose of the besylate salt of the compound offormula (I) is selected from the group consisting of between about 3 mgand about 10 mg; between about 3 mg and about 9 mg; and between about 5mg and about 8 mg.
 10. The method of claim 9, wherein the dose of thebesylate salt of the compound of formula (I) is about 5 mg.
 11. Themethod of claim 8, wherein the subject is undergoing an operativeprocedure.
 12. The method of claim 11, wherein the operative procedureis a diagnostic procedure.
 13. The method of claim 12, wherein thediagnostic procedure is an endoscopic procedure.
 14. The method of claim13, wherein the endoscopic procedure is colonoscopy.
 15. The method ofclaim 14, wherein the endoscopic procedure is upper GI endoscopy. 16.The method of claim 11, wherein the operative procedure is a therapeuticprocedure.
 17. The method of claim 8, wherein the besylate salt of thecompound formula (I) is administered to the subject intravenously. 18.The method of claim 17, wherein the besylate salt of the compound offormula (I) is administered to the subject in the form of a salinesolution.
 19. The method of claim 17, wherein the besylate salt of thecompound of formula (I) is administered to the subject over 1 minute.20. The method of claim 8, wherein the besylate salt of the compound offormula (I) is administered to the subject at a dose of between about 5mg to about 8 mg, and wherein the besylate salt of the compound offormula (I) to the subject is administered to the subject intravenouslyin the form of a saline solution over 1 minute.